Added get_issue_events , get_issue_timeline and get_issue_event tools

[artemsaveliev]

Implements 3 tools dealing with issue events and timeline:

• get_issue_events - all events for the issue https://docs.github.com/en/rest/issues/events?apiVersion=2022-11-28#list-issue-events-for-a-repository
• get_issue_timeline - issue events timeline https://docs.github.com/en/rest/issues/timeline
• get_issue_event - issue event details https://docs.github.com/en/rest/issues/events?apiVersion=2022-11-28#get-an-issue-event

[Copilot]

Pull Request Overview

This PR adds three new tools to handle GitHub issue events and timeline retrieval with associated tests and documentation updates.

• Added tool registrations in the server to support get_issue_timeline, get_issue_events, and get_issue_event.
• Implemented the corresponding functions in pkg/github/issues.go and added comprehensive tests in pkg/github/issues_test.go.
• Updated README.md to document the new tools.

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
pkg/github/server.go	Registers new tools and adds a helper function for int64 parameter conversion.
pkg/github/issues_test.go	Provides tests for the new tools covering success and error scenarios.
pkg/github/issues.go	Implements tool functions for issue timeline, events, and a single event retrieval.
README.md	Updates documentation for the new tools with expected input parameters.

Comments suppressed due to low confidence (2)

README.md:167

• The parameter name 'perPage' in the documentation does not match the tool definition which uses 'per_page'. Consider updating the README to use consistent naming.

- `perPage`: Results per page (number, optional)

pkg/github/issues_test.go:1434

• [nitpick] The test for 'get_issue_event' uses an event_id value of 42 while the expected mock event has a different ID (17196710688). Consider aligning the event_id values to avoid potential confusion.

"event_id": float64(42),