Change-Id: I625af65b3fb1815b1af17dc2ef47dd697fdc3fb1

Fixed regression caused by the combination of :ticket:`8177`, re-enable
setinputsizes for SQL server unless fast_executemany + DBAPI executemany is
used for a statement, along with :ticket:`6047`, implement
"insertmanyvalues", which bypasses DBAPI executemany in place of a custom
DBAPI execute for INSERT statements. setinputsizes would incorrectly not be
used for a multiple parameter-set INSERT statement that used
"insertmanyvalues" if fast_executemany were turned on, as the check would
incorrectly assume this is a DBAPI executemany call.  The "regression"
would then be that the "insertmanyvalues" statement format is apparently
slightly more sensitive to multiple rows that don't use the same types
for each row, so in such a case setinputsizes is especially needed.

The fix repairs the fast_executemany check so that it only disables
setinputsizes if true DBAPI executemany is to be used.

Fixes: #8917
Change-Id: I78895606a99848d4f92ecf38ded92dc5d6d48c6f

command run is "pyupgrade --py37-plus --keep-runtime-typing --keep-percent-format <files...>"
pyupgrade will change assert_ to assertTrue. That was reverted since assertTrue does not
exists in sqlalchemy fixtures

Change-Id: Ie1ed2675c7b11d893d78e028aad0d1576baebb55

Fixes: #8605
Change-Id: I4aec83b9f321462427c3f4ac941c3b272255c088

The ``use_setinputsizes`` parameter for the ``mssql+pyodbc`` dialect now
defaults to ``True``; this is so that non-unicode string comparisons are
bound by pyodbc to pyodbc.SQL_VARCHAR rather than pyodbc.SQL_WVARCHAR,
allowing indexes against VARCHAR columns to take effect. In order for the
``fast_executemany=True`` parameter to continue functioning, the
``use_setinputsizes`` mode now skips the ``cursor.setinputsizes()`` call
specifically when ``fast_executemany`` is True and the specific method in
use is ``cursor.executemany()``, which doesn't support setinputsizes. The
change also adds appropriate pyodbc DBAPI typing to values that are typed
as :class:`_types.Unicode` or :class:`_types.UnicodeText`, as well as
altered the base :class:`_types.JSON` datatype to consider JSON string
values as :class:`_types.Unicode` rather than :class:`_types.String`.

Fixes: #8177
Change-Id: I6c8886663254ae55cf904ad256c906e8f5e11f48

Fix issue where a password with a leading "{" would
result in login failure.

Fixes: #8062
Change-Id: If91c2c211937b5eac89b8d525c22a19b0a94c5c4

Change-Id: I42ed77f559e3ee5b8c600d98457ee37803ef0ea6

strict types type_api.py, including TypeDecorator,
NativeForEmulated, etc.

Change-Id: Ib2eba26de0981324a83733954cb7044a29bbd7db

this is much simplified, will try to see if _IsolationLevel
can work out, technically some driver can have custom values
here but in practice this might not be a thing

Change-Id: I6085ccb559c377fab03c8ce79f0eecb240c56f7a

All modules in sqlalchemy.engine are strictly
typed with the exception of cursor, default, and
reflection.  cursor and default pass with non-strict
typing, reflection is waiting on the multi-reflection
refactor.

Behavioral changes:

* create_connect_args() methods return a tuple of list,
  dict, rather than a list of list, dict
* removed allow_chars parameter from
  pyodbc connector ._get_server_version_info()
  method
* the parameter list passed to do_executemany is now
  a list in all cases. previously, this was being run
  through dialect.execute_sequence_format, which
  defaults to tuple and was only intended for individual
  tuple params.
* broke up dialect.dbapi into dialect.import_dbapi
  class method and dialect.dbapi module object.  added
  a deprecation path for legacy dialects.  it's not
  really feasible to type a single attr as a classmethod
  vs. module type.  The "type_compiler" attribute also
  has this problem with greater ability to work around,
  left that one for now.
* lots of constants changing to be Enum, so that we can
  type them.  for fixed tuple-position constants in
  cursor.py / compiler.py (which are used to avoid the
  speed overhead of namedtuple), using Literal[value]
  which seems to work well
* some tightening up in Row regarding __getitem__, which
  we can do since we are on full 2.0 style result use
* altered the set_connection_execution_options and
  set_engine_execution_options event flows so that the
  dictionary of options may be mutated within the event
  hook, where it will then take effect as the actual
  options used.  Previously, changing the dict would
  be silently ignored which seems counter-intuitive
  and not very useful.
* A lot of DefaultDialect/DefaultExecutionContext
  methods and attributes, including underscored ones, move
  to interfaces.  This is not fully ideal as it means
  the Dialect/ExecutionContext interfaces aren't publicly
  subclassable directly, but their current purpose
  is more of documentation for dialect authors who should
  (and certainly are) still be subclassing the DefaultXYZ
  versions in all cases

Overall, Result was the most extremely difficult class
hierarchy to type here as this hierarchy passes through
largely amorphous "row" datatypes throughout, which
can in fact by all kinds of different things, like
raw DBAPI rows, or Row objects, or "scalar"/Any, but
at the same time these types have meaning so I tried still
maintaining some level of semantic markings for these,
it highlights how complex Result is now, as it's trying
to be extremely efficient and inlined while also being
very open-ended and extensible.

Change-Id: I98b75c0c09eab5355fc7a33ba41dd9874274f12a