[Feature] GitHub Search integration enabling users to search for Issues and Pull Request #12

Why do we need this ?

As a GitHub App developer

I need to: Add a search feature which enables users to query issues and pull requests

So That: users can search for relevant Pull Requests and Issues right from Rocket.Chat and share them in the desired channel, enhancing the communication and collaboration between developers.

Acceptance Criteria

• Enable user to trigger a search modal using /github search.
• Enable user to enter search queries and fetch relevant results.
• User Should be able to view and select the relevant search results in a another search view modal.
• Users should be able to send selected search result in the desired room.
• Add documentation to the wiki for the GitHub search mechanism and user-flow
• Handle non authenticated users edge cases. (GitHub Search API requires OAuth Token)

Further Comments / Referances

• GSoC Proposal mentioned the search result to be fetched directly in chat but viewing them in a modal and sending relevant results to the channels seems like a better user experience.
• Wireframes for the Search Modal Mentioned in the Google Summer of Code Proposal :