[Cosmos] Api review follow-ups

[simorenoh]

• update the typing of excluded_locations: Optional[list[str]] to excluded_locations: Optional[Sequence[str]] across the SDK
• _PartitionKeyType was made private - which doesn't make sense if it applies to all the public APIs that use partition keys. we should likely expose this instead:

• methods like get_conflict still say they return Dict[str, Any] even thought they also return CosmosDict at this point - we should go through all the public APIs and verify that their return types are updated to reflect this if it applies (at this point it should apply to most methods)
• overloads for the query_items methods are all missing return types
• query_items overloads should be updated to reflect the behavior being outlined here:

• default max_concurrency value for any default threadpool usage (only read_items right now I believe) should be made optional, and left to the default value in the native Python library unless customers have the resources/ want to set it higher:

• replace_throughput method had the response_hook taken away - which is a breaking change. need to add this back:

• new InternalException should be marked as private by using an underscore, since it should not be something for users to use
• re-add SERVICE_UNAVAILABLE = 503 to the constants file - it was probably removed due to it being un-used, but it will now have special casing with PPAF anyway
• update CosmosDict and CosmosList to only inherit the built-in type for dict and list respectively instead of the current typing variant - as well as change List and Dict imports
• update minimum version to 3.9 aligning with the above as well - Core dropped support for 3.8 already 6 months ago [Core] Drop Python 3.8 support #40831:

• the new overloads added for the create_database and create_database_if_not_exists methods missed the response_hook arg being included, as well as including some enhancements that were previously mentioned:

• The typehint for ConsistencyPolicy in docstring and actual code were mismatching. Fix mismatching type of ConsistencyPolicy with docstring.

[andrewmathew1]

Adding response_hook to the replace_throughput method: #43243

[simorenoh]

First PR:

• re-add SERVICE_UNAVAILABLE = 503 to the constants file - it was probably removed due to it being un-used, but it will now have special casing with PPAF anyway
• new InternalException should be marked as private by using an underscore, since it should not be something for users to use
• update the typing of excluded_locations: Optional[list[str]] to excluded_locations: Optional[Sequence[str]] across the SDK
• _PartitionKeyType was made private - which doesn't make sense if it applies to all the public APIs that use partition keys. we should likely expose this instead
  [Cosmos] make PartitionKeyType public, mark excluded locations as sequence, make InternalException private #43235

Second PR:

• update CosmosDict and CosmosList to only inherit the built-in type for dict and list respectively instead of the current typing variant - as well as change List and Dict imports:
• Updating the minimum Python version to 3.9 to align with Core SDKs guidelines.
  [Cosmos] refactor dict and list #43244

[allenkim0129]

Working on query_items releated items #43240:

• overloads for the query_items methods are all missing return types
• query_items overloads should be updated to reflect the behavior being outlined here

Working on updating return type to CosmosDict #43254
:

• methods like get_conflict still say they return Dict[str, Any] even thought they also return CosmosDict at this point - we should go through all the public APIs and verify that their return types are updated to reflect this if it applies (at this point it should apply to most methods)

Working on fixing type hint for ConsistencyPolicy #43150:

• The typehint for ConsistencyPolicy in docstring and actual code were mismatching. Fix mismatching type of ConsistencyPolicy with docstring.

[bambriz]

If these two haven't been picked up, I'll go ahead and tackle them on.

1. default max_concurrency value for any default threadpool usage
2. new overloads added for the create_database and create_database_if_not_exists methods missed the response_hook arg being included