[tools, cmake] refactor: update/hash check scripts, use tags for some more deps, proper CPMUtil separation (#2666)

Uses tags for a bunch of deps that can use them

Also adds a bunmch of scripts to tools/cpm, notably for checking hashes
and checking for updates.

TODO for the future:
- CI target to check hashes
- Weekly CI to check for updates

Need to get that other CI runner up

additional stuff

- Ports gentoo fixes
- makes solaris work (TODO: sdl2)
- way better docs
- properly separates CPMUtil as a standalone project

Reviewed-on: #2666
Reviewed-by: Lizzie <lizzie@eden-emu.dev>
Reviewed-by: MaranBr <maranbr@eden-emu.dev>

README.md

@@ -63,6 +63,8 @@ Alternatively, if you wish to add translations, go to the [Eden project on Trans
 
 See the [General Build Guide](docs/Build.md)
 
+For information on provided development tooling, see the [Tools directory](./tools)
+
 ## Download
 
 You can download the latest releases from [here](https://github.com/eden-emulator/Releases/releases).