Core functionality gaps in Shape Layers, Effect Controls, and Project Panel

Apologies if this needs to be split into multiple issues; these were just my general notes on things that were missing from the typical AE experience:

## Shape Layers

- [ ] Add the **Contents > Add** menu.
- [ ] Add **Fill Options** and **Stroke Options**.
- None / Solid Color / Gradient / Radial Gradient / Layer Styles / Opacity
- [ ] Add **Tool Creates Shape** and **Tool Creates Mask** options to the toolbar when the Shape/Pen Tool is in use.
- [ ] Support multiple shapes/layers within **Shape Layer(s) > Contents**.
- [ ] Allow adding basic shapes and other **Shape Layer > Contents** items into empty Shape Layers.
- Currently, the **Pen Tool** can add a path, but creating other basic shapes generates a new Shape Layer.
- [ ] Allow copying and pasting **Contents** between Shape Layers.
- The Pen Tool can add multiple Contents items, but copying and pasting them between Shape Layers does not work.
- [ ] Fix `Ctrl + X` / `Ctrl + V` behavior for Contents items.
- Cutting works, but pasting creates a new Shape Layer instead of inserting the Contents item.
- [ ] Fix `Ctrl + D` behavior for Contents items.
- Currently duplicates the entire Shape Layer instead of the selected Contents item.
- [ ] Investigate **Effects > Turbulent Displace** only affecting shapes in the bottom-right quadrant.

## Effect Controls

- [ ] Add right-click context menu support within the **Effect Controls** panel to show/select effects.

## Project Panel

- [ ] Add right-click context menu op...