Shinywidgets

* Fixed an issue where widgets would sometimes fail to render in a Quarto document. (159)
* Fixed an issue where importing shinywidgets before a ipywidget implementation can sometimes error in a Shiny Express app. (163)

* Fixed a bug with receiving binary data on the frontend, which gets [quak](https://github.com/manzt/quak) and [mosaic-widget](https://idl.uw.edu/mosaic/jupyter/) working with `render_widget`. (#152)

* Fixed a bug with multiple altair outputs not working inside a `shiny.render.ui` decorator. (140)
* `render_widget` no longer errors out when giving a `altair.FacetChart` class. (142)
* `render_widget` no longer fails to serialize `decimal.Decimal` objects. (138)

* Widgets no longer have a "flash" of incorrect size when first rendered. (133)
* `render_widget` now works properly with `Widget`s that aren't `DOMWidget`s (i.e., widgets that aren't meant to be displayed directly). As a result, you can now use `render_widget` to gain a reference to the widget instance, and then use that reference to update the widget's value. (133)

* The `render_widget` decorator now attaches a `widget` (and `value`) attribute to the function it decorates. This allows for easier access to the widget instance (or value), and eliminates the need for `register_widget` (which is now soft deprecated). (119)
* Added decorators for notable packages that require coercion to the `Widget` class: `render_altair`, `render_bokeh`, `render_plotly`, and `render_pydeck`. Using these decorators (over `render_widget`) helps with typing on the `widget` attribute. (119)
* The `.properties()` method on `altair.Chart` object now works as expected again. (129)
* Reduce default plot margins on plotly graphs.

* Fixed several issues with filling layout behavior introduced in 0.2.3. (124, 125)
* `reactive_read()` now throws a more informative error when attempting to read non-existing or non-trait attributes. (120)