Add initial implementation of primary menu

I'm adding an early version of the wireframes to bring more clarity on what is the direction in terms of UI design. There's no need to implement this pixel perfect, or try to derive capabilities from it. It's a mid-fi wireframe that is showcasing many future possibilities and making sure that the UI can sufficiently accommodate those.

hooroomoo → credited jessebaker → .

hooroomoo → credited larowlan → .

I don't see any issue for the follow-ups defined in the MR description? 😅

To be done in a followup(s):

• Close the menu one drags a component from on drag so the menu is not taking up so much space on the canvas
• Style the draggable components so they look draggable
• Other styling/micro-interactions such as being able to also close the third level submenu on click.
• SVG icon optimization
• Search bar functionality
• Test for dragging a component into the canvas
• A11y check

1. Close the menu one drags a component from on drag so the menu is not taking up so much space on the canvas

Addressed at [#/3458617]

2. Style the draggable components so they look draggable

Probably don't have to worry about this right now at this stage.

3. Other styling/micro-interactions such as being able to also close the third level submenu on click.

Addressed at ✨ Close submenu on drag in primary menu Needs work

4. SVG icon optimization

Created issue 📌 Replace icons with optimized SVGs Active

5. Search bar functionality

Created issue 📌 Implement search functionality to the primary menu Active

6. Test for dragging a component into the canvas

Test can be added when bug 🐛 Dragging in components that ship with xb doesn't load anymore Active is fixed, already marked with Needs tests

7. A11y check

This can come when XB is further along

Linking the follow-ups @hooroomoo created, for easier discoverability.

Automatically closed - issue fixed for 2 weeks with no activity.