fix: `/gh issues` unrecognised by command utility

[henit-chobisa]

Issue(s)

The issues modal triggered by /gh issues, showing the current issues of a given respository was implemented but the case for triggering the same from command utility was not handled.

Acceptance Criteria fulfillment

• [x] Make a new function in IssuesHandler for launching the issues modal, named as handleIssues
• [x] Trigger the above mentioned function in singular param commands in the command utility on case SubcommandEnum.Issues

Proposed changes (including videos or screenshots)

https://user-images.githubusercontent.com/72302948/220573788-6390d57e-d0de-4767-9bcd-a6204f42c50b.mov

[henit-chobisa]

Hey @samad-yar-khan & @Sing-Li, I have fixed the /gh issues command that was not working before 🔫 Kindly review ✌️