feat: add configuration for transparent session re-init

[glicht]

Motivation and Context

Providing control if to enable transparent session re-init. Added to StreamableHttpClientTransportConfig a new field: enable_reinit_on_expired_session to control if to do transparent session re-init.

How Has This Been Tested?

Added a unit test: test_session_expired_error_when_reinit_disabled and updated current unit test: test_transparent_reinitialization_on_session_expiry.

New config option is documented as part of the docs for StreamableHttpClientTransportConfig.

Breaking Changes

No

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update

Checklist

• I have read the MCP Documentation
• My code follows the repository's style guidelines
• New and existing tests pass locally
• I have added appropriate error handling
• I have added or updated documentation as needed

Additional context

Closes #755

[glicht]

I originally added to ci.yml also running tests without the local feature as many tests weren't running during ci as they had: not(feature = "local"). But we have a failing test: test_custom_client_request_reaches_server.

So I reverted this addition. I've opened a separate PR for running the non-local tests here.

[DaleSeo]

Thank you for adding this configurability, @glicht! I have a comment on the default value choice.

[glicht]

Thank you for adding this configurability, @glicht! I have a comment on the default value choice.

I've updated following your comments.