Lab blocks

[RandomCyberCoder]

Description of the change

Labs and activities time can now be placed all into one block.

constraints added

• modified/added constraints to allow the major change to happen
• added a constraint aiming to promote instances of a course to be spread out. Additional logic can be added so gorups of courses can also be considered here
• added a constraint that won't allow an instructor to teach for more than six consecutive hours

Checklist

Development

• The changes have been covered with tests, if necessary.
• You have a green build
• Backend tests passed

Code Review

• This pull request includes an explanatory title and description.
• The GitHub issue is linked if necessary