Feat: Add gitlab get_project command

[MartimPimentel]

Motivation and Context

Add get_project functionality to the GitLab MCP server, allowing retrieval of GitLab project details by project ID or URL-encoded path. This includes updates to the server logic, schemas, and documentation.

Also adds a new merge_requests_template parameter to the GitLabRepositorySchema, so that the get_project command can also retrieve this information.

This change is needed to enable clients to fetch detailed information about a specific GitLab project, which is essential for project management and integration scenarios. As an example, imagine that we want to retrieve the merge request template setup on the project data, this command would be able to easily retrieve it to be later used to create a new merge request with that data.

How Has This Been Tested?

Manual testing with the MCP server configured on a project I owned together with LLMs (claude sonnet, gpt 4.1) client to verify the new get_project tool returns correct project details for valid project IDs (either with the project id or project complete path.

Breaking Changes

No breaking changes. Existing client configurations remain compatible.

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 Protocol Documentation
• My changes follows MCP security best practices
• I have updated the server's README accordingly
• I have tested this with an LLM client
• My code follows the repository's style guidelines
• New and existing tests pass locally
• I have added appropriate error handling
• I have documented all environment variables and configuration options

Additional context

Adds a new tool to the GitLab MCP server for retrieving project details, updates schemas, and documents the new endpoint in the server README.

[olaservo]

Thanks for contributing this PR. This server has been moved to the archived repository at https://github.com/modelcontextprotocol/servers-archived to reduce maintenance overhead, so we can focus our efforts on a smaller set of core servers.
Since we're no longer accepting contributions to this server, we won't be able to merge this PR. If you're interested in contributing similar functionality, we recommend checking out the alternatives listed in the Readme.