EXP-1822 FIXED (After deleting an item from inventory and confirming "ok" to delete, focus leaves inventory)

-Return focus to the previously focused view

 more layout logic fixes and added renormalization to fractional sizes to eliminate drift

- Made splitter draggable to ~75%
- Decreased min width of navigation layout panel for user convenience, so that user can make favorites bar bigger and see more favorite landmarks at a time.

 fixed layout logic when dealing with invisibile layout_panels

cleaned up font positioning on buttons

EXP-1847 FIXED Fixed inability to mute a nearby avatar in Voice Settings if the speakers list is sorted by name.

Added missing update of the floater's internal speaker list.

EXP-1846 FIX Text positioning issues in Floaters, Notifications, UI, and toasts with UI size smaller than 1
also, re-enabled floater_test_textbox.xml

EXP-1839 FIXED Fixed treating normal nearby speakers as text-only chat participants which led to marking muted avatars as non-muted.

Added filtering the items on DnD, allowing to drop only the items which pass the filter in the destinatination inventory panel.
Added filtering the items from object contents and notecards.
Changed handle type for LLInventoryPanel in LLInvFVBridge to remove some extra dynamic casts.

Use the same on_click/on_enable actions as for the other attachment points.
See LLVOAvatarSelf::buildMenus().

added logging to track length of time spent reading notifications templates

removed O(n^2) comparisons of XML nodes in favor of O(n)

Moved coordinate mode combo back into main build floater from sub-floater.

Reverting background fetch on an item to the old fetFromServer call to fix regression bug in inventory late loading

Reverting rev 22217 changes to background fetch so search and recent will fully fetch user inventory

EXP-1799 FIX -- Replace and Add to Outfit options and Copy to Merchant Outbox options can appear in invalid state when a valid folder is last selection
EXP-1834 FIX -- Right click context menus on Folders in Merchant Outbox and Library folders can show all inventory options including admin options
EXP-1835 FIX -- Right clicking on a folder and selecting New Folder creates folder under My Inventory not within selected folder

* Updated folder context menu building to build full options in one step or
  trigger a load which will rebuild top-level context menu for all selected
  items when complete.  Previous code had an implicit assumption that the
  selected folder was the only selection after background fetch.

Restoring mistakenly removed code.

EXP-1821 FIXED Don't open group chat for the selected group if user double-clicks on empty space in the group list.