mgr/dashboard: Pool create / edit

mgr/dashboard: Pool create / edit

You can create/edit pools through the UI if you have the right
permissions.

You can specify the following:
* Name - can't be duplicated
* Type - replicated or erasure
* Crush rule set
  * Validates if you can use it
  * A popover tells which crush steps are used
* Replica size - depends on your selected rule and the amount of OSDs
* Erasure code profile
* PGs - will be recalculated on form changes (type, replica size,
    erasure profile, crush rule) only if not set before
* EC overwrites flag
* Compression - Algorithm / Min/max blob size / mode / ratio
* Application metadata - Predefined and custom applications as badges

Fixes: https://tracker.ceph.com/issues/36355
Signed-off-by: Stephan Müller <smueller@suse.com>