Detailed table PR analytics for graph, and many other wonders...

✨ New

• Created a page for each analytics where we can see each pull requests that were taken into account with specific data.
• Allowing some bots to send messages in pull request channels.
• Label manager is now operationnal! Define Axolo behavior upon specific GitHub labels.

🔨 Improvements

• Reminders are now computed upon inactivity of business days only.
• Added tips in the onboarding Slack message about Axolo home and the /lgtm command.
• Taking into account only merged PR in the PR length graph.

🐞 Fixes

• Bug line number in code review comment where Axolo was using the wrong line number (this line within the review instead of within the entire file)
• Fixed the invite later using engineers' timeslots for code reviews.