* Simplify and speedup dev node startup

This patch introduces an escript that generates an Erlang .boot script
to start CouchDB using the in-place .beam files produced by the compile
phase of the build. This allows us to radically simplify the boot
process as Erlang computes the optimal order for loading the necessary
modules.

In addition to the simplification this approach offers a significant
speedup when working inside a container environment. In my test with
the stock .devcontainer it reduces startup time from about 75 seconds
down to under 5 seconds.

* Rename boot_node to monitor_parent

* Add formatting suggestions from python-black

Co-authored-by: Paul J. Davis <paul.joseph.davis@gmail.com>

* Add support for specify a custom config file for CouchDB startup during testing
* Port proxyauth test from js to elixir

* Added db initialization for standalone instance

* Test setup

* Updated readme

* Added standalone option to rel/overlay/etc/default.ini

* Simplified test setup

* s/standalone/single_node/

Co-authored-by: Jan Lehnardt <jan@apache.org>

Sometimes there is a need to specify additional arguments for the beam process we start from dev/run.
In particular the feature is handy for:
- changing emulator flags
- simulate OOM via available RAM restrictions
- enable module loading tracing
- configure number of schedulers
- modify applications configuration
- run customization script to add extra development deps (such as automatic code reload)

Historically developers had to edit dev/run to do it.
This PR adds an ability to specify additional arguments via `--extra_args` argument.

In order to run customization script create `customization.erl` which exports `start/0` and run it using:
```
dev/run --extra_args='-run customization'
```