[Cosmos] version upgrade for release (Azure#22765)

* initial commit

* Client Constructor (Azure#20310)

* Removed some stuff

* Looking at constructors

* Updated request

* Added client close

* working client creation

Co-authored-by: simorenoh <simonmorenohe@gmail.com>

* read database

database read works, but ignored exception is returned:
Fatal error on SSL transport
NoneType has no attribute 'send' (_loop._proactor.send)
RuntimeError: Event loop is closed
Unclosed connector/ connection

* Update simon_testfile.py

* with coroutine

Added methods needed to use async with when initializing client, but logs output "Exception ignored... Runtime Error: Event loop is closed"

* Update simon_testfile.py

* small changes

* async with returns no exceptions

* async read container

* async item read

* cleaning up

* create item/ database methods

* item delete working

* docs replace functionality

missing upsert and other resources

* upsert functionality

missing read_all_items and both query methods for container class

* missing query methods

* CRUD for udf, sproc, triggers

* initial query logic + container methods

* missing some execution logic and tests

* oops

* fully working queries

* small fix to query_items()

also fixed README and added examples_async

* Update _cosmos_client_connection_async.py

* Update _cosmos_client_connection.py

* documentation update

* updated MIT dates and get_user_client() description

* Update CHANGELOG.md

* Delete simon_testfile.py

* leftover retry utility

* Update README.md

* docs and removed six package

* changes based on comments

still missing discussion resolution on SSL verification and tests for async functionality under test module (apart from samples which are basically end to end tests)

* small change in type hints

* updated readme

* fixes based on conversations

* added missing type comments

* update changelog for ci pipeline

* added typehints, moved params into keywords, added decorators, made _connection_policy private

* changes based on sync with central sdk

* remove is_system_key from scripts (only used in execute_sproc)

is_system_key verifies that an empty partition key is properly dealt with if ['partitionKey']['systemKey'] exists in the container options - however, we do not allow containers to be created with empty partition key values in the python sdk, so the functionality is needless

* Revert "remove is_system_key from scripts (only used in execute_sproc)"

Reverting last commit, will find way to init is_system_key for now

* async script proxy using composition

* pylint

* capitalized constants

* Apply suggestions from code review

Clarifying comments for README

Co-authored-by: Gahl Levy <75269480+gahl-levy@users.noreply.github.com>

* closing python code snippet

* last doc updates

* Update sdk/cosmos/azure-cosmos/CHANGELOG.md

Co-authored-by: Simon Moreno <30335873+simorenoh@users.noreply.github.com>

* version update

* cosmos updates for release

* fix connection string comma

* Update CHANGELOG.md

Co-authored-by: annatisch <antisch@microsoft.com>
Co-authored-by: Gahl Levy <75269480+gahl-levy@users.noreply.github.com>
Co-authored-by: Travis Prescott <tjprescott@users.noreply.github.com>

sdk/cosmos/azure-cosmos/CHANGELOG.md

@@ -1,6 +1,6 @@
 ## Release History
 
-### 4.3.0b2 (Unreleased)
+### 4.3.0b2 (2022-01-25)
 
 This version and all future versions will require Python 3.6+. Python 2.7 is no longer supported.
 We will also be removing support for Python 3.6 and will only support Python 3.7+ starting December 2022.