Workfiles tool: Refactor workfiles tool (for AYON) (#5550)

* ayon workfiles tool initial commit

* separated models into smaller files

* workfile can be listed and opened

* added browse logic

* added TODO for helper functions

* modified abstract controller

* implemented required methods

* base of save dialog

* added project settings to controller

* set context of side panel on init

* implemented save as dialog

* cleanup expected selection

* unify controller variable name

* base of published workfiles

* working published workfile copy

* added more missing features from workfiles tool

* Changed size policy of buttons to fill space vertically

* added overlay messages

* moved objects to abstraction

* moved 'window.py' to widgets

* small modifications in widgets

* get_workfile_info returns object

* filled docstrings in abstractions

* finishing touches

* backwards compatible work with host

* close window on successfull open

* remove indentation completelly

* added style for overlay label

* added handling of invalid host in controller

* added overlay with message if host is not valid

* added missing feature of disabled save

* use ayon_workfiles in ayon mode

* cleanup

* hound fixes

* use asset doc for 'change_current_context'

* added duplication action

* removed unused attributes and methods

* refresh workarea view on save as finished

* support host integrations without 'HostBase'

* fix 'filepath' fill

* reset item cache on save

* do not handle filepath in prepare workfile

* rename '_create_workfile_doc' > '_create_workfile_info_entity'

* fill comment before formatting

* fix column count by not calling 'clear'

* more explicit name of method

* use 'setHeaderData' to define header labels

* mimic changes from workarea widget in published widget

openpype/style/style.css

@@ -1427,6 +1427,10 @@ CreateNextPageOverlay {
     background: rgba(0, 0, 0, 127);
 }
 
+#OverlayFrameLabel {
+    font-size: 15pt;
+}
+
 #BreadcrumbsPathInput {
     padding: 2px;
     font-size: 9pt;