Support mutlipe backup targets on UI

[a110605]

What this PR does / why we need it

Support mutlipe backup targets feature in longhorn UI

Longhorn UI change Items

• Backup & backup detail page should display correctly since some API schemes changed
• Add new page in Settings -> Backup Target
  - Display all backup targets in a table
  - Allow user to create new backup target
  - delete / edit existing item
  - bulk delete
  - filter backup target on page top right
• allow user to choose backup target when creating backup task recurring job.
• allow user to choose backup target when creating backup in volume detail page.
• allow user to choose backup target when creating backup backing image
• Disable create backup in volume detail / backup / system backup pages if no available and writable backup targets

Note. This UI PR need to wait for longhorn-manager and LEP PRs merge first.

• feat(lep): multiple backup stores support longhorn#6630
• feat(backup): multiple backup stores support longhorn-manager#2182

Issue

[UI][FEATURE] Multiple backup stores support

Test Result

Backup detail page should display correct backups (the backup belongs to that backup target)

CRUD operations in Settings -> Backup Target page

backuptarget-crud.mov

Allow user to choose backup target when creating backup task recurring job.

recurring-job.mov

Allow user to choose backup target when creating backup in volume detail page

volume-create-backup.mov

Allow user to choose backup target when creating backup backing image

backingimagebackup.mov

Additional documentation or context

[mergify]

This pull request is now in conflict. Could you fix it @a110605? 🙏