Fixes #14563 - Improve dashboard layout

The css used for calculating the dashboard layout is overcomplicated and
does not allow for more then 8 rows of widgets without breaking.
This PR cleans up useless code, allows up to 30 rows to be correctly
displayed, and displays widgets that are being dragged instead of only...

Fixes #14572 - fix updating storage in compute profiles based on template

Fixes #14451 - Allow plugins to add menus to top menu without breaking the second menu

fixes #14202 - enable select2 in interfaces modal

Reverts commit 44723b9 and re-enables select2 in the interfaces modal,
instead fixing the issue with the NIC table detail lines to read the
network information out of select2 dropdown menus correctly.

Fixes #14341 - List all images for compute resource

Previously, the listing was paginated, but since the table is loaded
via ajax and handled by datatables, the pagination had no effect,
leading to a list limited to the max per page (20 usually).
Also, improved the lookup to only bring the needed data.

fixes #12962 - Add Xenserver to list of supported OS families.

Templates are included in community-templates repo.

Fixes #12979 - Create helper for "new" button

Previously the button classes were applied to new buttons using jQuery.
This commit creates a `new_link` helper that makes sure all new buttons
will receive the correct class and only display if authorized. Also a...

fixes #14318 - load JS translations table for current locale only

fixes #14041 - don't call select2 on CR form templates

select2 must be called only when the select becomes visible, not for
hidden template elements. add_child_node() already does when adding a
new set of fields from the template. without_select2 is removed from...

Refs #7726 - Improve select all for filtered multi-select