[GT-187] Add support for selecting mutiple sites

[Sae126V]

• Added support for selecting multiple sites in "ADD" downtime.
• Changed the Confirm Downtime and Confirm Edit Downtime pages.
• Changed Add_Downtime success page with relevant content.

Resolves: https://github.com/GOCDB/gocdb/issues/261

Partially address: https://github.com/GOCDB/gocdb/issues/85 and https://github.com/GOCDB/gocdb/issues/66 .

Addressed @gregcorbett comments:

### Suggestion 1: Include the Site Name next to the downtime link on creation, i.e.:

New Downtimes successfully created. Please click the links below for more information.

• Site A: Downtime 10
• Site B: Downtime 11

### Suggestion 1: Only display the start and end time once on the "Confirm Downtime" page, i.e.:

Severity: WARNING Description: foo bar Starting (UTC): 08/09/2023 00:00 Ending (UTC): 18/09/2023 00:00 Site Name: Brunnen GS ... Site Name: Torch ...

[gregcorbett]

Has #475 superseded this PR?

[Sae126V]

Has #475 superseded this PR?

This PR is Having Mix and match of addressing PSR-12 issues mostly, it includes function level refractor(Minor improvements) etc. It is in draft as of now. Until I take a pull from dev to clear blockers for this.

[tofu-rocketry]

Has #475 superseded this PR?

This PR is Having Mix and match of addressing PSR-12 issues mostly, it includes function level refractor(Minor improvements) etc. It is in draft as of now. Until I take a pull from dev to clear blockers for this.

If that's the case, can you then update the title and description, and make it clear what PR it's waiting on to be merged first?