add backend agnostic UUID datatype

Added new backend-agnostic :class:`_types.Uuid` datatype generalized from
the PostgreSQL dialects to now be a core type, as well as migrated
:class:`_types.UUID` from the PostgreSQL dialect. Thanks to Trevor Gross
for the help on this.

also includes:

* corrects some missing behaviors in the suite literal fixtures
  test where row round trips weren't being correctly asserted.
* fixes some of the ISO literal date rendering added in
  952383f9ee0 for #5052 to truncate datetime strings for date/time
  datatypes in the same way that drivers typically do for bound
  parameters; this was not working fully and wasn't caught by the
  broken test fixture

Fixes: #7212
Change-Id: I981ac6d34d278c18281c144430a528764c241b04

1 files changed, 0 insertions, 19 deletions

diff --git a/lib/sqlalchemy/dialects/postgresql/_psycopg_common.py b/lib/sqlalchemy/dialects/postgresql/_psycopg_common.py
index 6b8b3f6d0..e831f2ed9 100644
--- a/lib/sqlalchemy/dialects/postgresql/_psycopg_common.py
+++ b/lib/sqlalchemy/dialects/postgresql/_psycopg_common.py
@@ -8,7 +8,6 @@ from .base import _FLOAT_TYPES
 from .base import _INT_TYPES
 from .base import PGDialect
 from .base import PGExecutionContext
-from .base import UUID
 from .hstore import HSTORE
 from ... import exc
 from ... import types as sqltypes
@@ -63,21 +62,6 @@ class _PsycopgHStore(HSTORE):
             )
 
 
-class _PsycopgUUID(UUID):
-    def bind_processor(self, dialect):
-        return None
-
-    def result_processor(self, dialect, coltype):
-        if not self.as_uuid and dialect.use_native_uuid:
-
-            def process(value):
-                if value is not None:
-                    value = str(value)
-                return value
-
-            return process
-
-
 class _PsycopgARRAY(PGARRAY):
     render_bind_cast = True
 
@@ -106,7 +90,6 @@ class _PGDialect_common_psycopg(PGDialect):
         {
             sqltypes.Numeric: _PsycopgNumeric,
             HSTORE: _PsycopgHStore,
-            UUID: _PsycopgUUID,
             sqltypes.ARRAY: _PsycopgARRAY,
         },
     )
@@ -115,14 +98,12 @@ class _PGDialect_common_psycopg(PGDialect):
         self,
         client_encoding=None,
         use_native_hstore=True,
-        use_native_uuid=True,
         **kwargs,
     ):
         PGDialect.__init__(self, **kwargs)
         if not use_native_hstore:
             self._has_native_hstore = False
         self.use_native_hstore = use_native_hstore
-        self.use_native_uuid = use_native_uuid
         self.client_encoding = client_encoding
 
     def create_connect_args(self, url):