feat: add support for `conversations.requestShared` `approve` and `deny`

[WilliamBergamin]

Summary

⚠️ Work in progress

This PR aims to introduce support for conversations.requestShared.approve/deny API methods

Testing

N/A

Category

• [x] slack_sdk.web.WebClient (sync/async) (Web API client)
• [ ] slack_sdk.webhook.WebhookClient (sync/async) (Incoming Webhook, response_url sender)
• [ ] slack_sdk.socket_mode (Socket Mode client)
• [ ] slack_sdk.signature (Request Signature Verifier)
• [ ] slack_sdk.oauth (OAuth Flow Utilities)
• [ ] slack_sdk.models (UI component builders)
• [ ] slack_sdk.scim (SCIM API client)
• [ ] slack_sdk.audit_logs (Audit Logs API client)
• [ ] slack_sdk.rtm_v2 (RTM client)
• [ ] /docs-src (Documents, have you run ./scripts/docs.sh?)
• [ ] /tutorial (PythOnBoardingBot tutorial)
• [ ] tests/integration_tests (Automated tests for this library)

Requirements

• [x] I've read and understood the Contributing Guidelines and have done my best effort to follow them.
• [x] I've read and agree to the Code of Conduct.
• [x] I've run python3 -m venv .venv && source .venv/bin/activate && ./scripts/run_validation.sh after making the changes.

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 53.33333% with 21 lines in your changes missing coverage. Please review.

Project coverage is 84.85%. Comparing base (062b8c2) to head (4568864). Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
slack_sdk/web/async_client.py	53.33%	7 Missing :warning:
slack_sdk/web/client.py	53.33%	7 Missing :warning:
slack_sdk/web/legacy_client.py	53.33%	7 Missing :warning:

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1530      +/-   ##
==========================================
- Coverage   85.04%   84.85%   -0.20%     
==========================================
  Files         113      113              
  Lines       12501    12546      +45     
==========================================
+ Hits        10632    10646      +14     
- Misses       1869     1900      +31     

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.

[srajiang]

Not a blocker, but are we planning on releasing this after the methods are public?