New bug selection phase requirement

[Eclipse-Dominator]

Is your feature request related to a problem? Please describe.
Currently, there is no intermediate phase for selecting the top 7 bugs to be submitted to the development team between the bug reporting and developer response phases in CS2103. This leads to a lack of clarity and control in narrowing down the critical bugs for submission.

Proposed solution
The new Bug Selection Phase should:

1. View all reported bugs.
2. Allow teams to select the top X bugs (default 7) for submission.
3. Proceed with the selected bugs to the next phase (dev response).

[damithc]

Some further clarifications:

• The max bug count can vary from semester to semester (or from course to course) -- so, it should not be enforced in CATcher.
• Should not allow changing bug subject or body, but should allow changing labels.
• Should be able to delete (or close) bugs
• Students should be able to see a list of 'deleted' (i.e., closed) bugs to 'undelete' (i.e., reopen) them.