feat: add support to push local commits (push_commits tool)

[thiagoscodelerae]

Describe the feature or problem you’d like to solve

It would be beneficial to have an option to push local commits to a branch. This is particularly useful for the pull request scenario, where the user creates a branch, pushes commits, and opens a PR based on it.

• create_branch
• push_commits
• create_pull_request

Currently, there is no option to push local commits using the MCP tools; the only similar tool available is push_files.