Add module statistics viewer

[malmeloo]

Adds a module statistics viewer for Yosys. It currently supports these views:

• Module overview, which shows an overview of all the modules in a table format;
• Module explorer, which shows statistics for one module at a time, but allows the user to navigate "up and down" through the module structure.
• Primitives overview, which shows which and how many primitives make up each module.

All of these views are interactive and customizable: the user can add, remove and customize table grid columns, as well as navigate through the module structure and highlight these modules from the (separate) DigitalJS view.

The following fundamental module statistics can currently be explored:

• Memory count
• Memory bit count
• Cell count
• Process count
• Wire count
• Wire count (pub)

Note that this PR modifies the file structure of the files generated during Yosys synthesis. *.digitaljs.json files now have the following structure:

{
	"type": "rtl" | "stats",
	"data": "<original file content>"
} 

This allows using a single file viewer and then distinguishing between file types in the viewer itself, which makes it easier to facilitate cross-view messaging (to improve integration with DigitalJS, for example).

Changelogs

October 29th, 2023 (current)

1. Added more settings
2. Settings are now saved in between stat viewer sessions
3. Explorer tab is now focused when clicking the inspect button from DigitalJS
4. Stability + performance improvements

October 15th, 2023

Added a "primitives" tab as well as settings checkboxes.

October 8th, 2023

TODO

• Switch back to using tilk's DigitalJS instead of our own fork (dependent on Add navigation history to subcircuit click event tilk/digitaljs#101)
• Add more fundamental stats, such as wire count
• Anything else?

Closes #8.