Release notes for 573

Makes SharedTable a recognized type in Script analysis, preventing the incorrect unrecognized global error in Studio when SharedTable is used.

Fix to "/" hotkey focus issue for text input bar focus

In the Advanced Explorer Filter beta, adds a button to help autocomplete commonly used advanced filters.

Adds "Stack Lines" option to Output widget which, when unchecked, prevents lines from stacking together.

Customized package attributes now display in bold in the Properties pane. The original name of renamed packages also displays in the Explorer pane.

Allows developers to select how the rest pose is calculated during animation import with the 3D Importer.

Adds a way to return nil to Lua in the reflection system. Various functions will now return nil instead of doing a no op. For example, Instance:GetAttribute('ThisAttributeDoesNotExist') returns nil.

Fixes a subtyping failure when unifying an optional free type with itself, which resulted in Type contains a self-recursive construct errors.

Occluded outlines should continue to render with lighter opacity when constraints rendered in view.

Fixes performance issue with expanding and collapsing tables in the Output window.

Instance attributes now support Enum-typed values. The properties pane has the expected dropdown editor for these attributes.

Fixes an issue where using "Try In Studio" on the web duplicates the asset when entering play mode.