Improve project structure and build system

[pascalecu]

What I have done here is to:

• move the src/discord files around into a more logical structure
• added corresponding filters in VS, as well as filters for the Windows dir (I didn't feel the need to reorder the files there, since I am not touching that part of the source code)
• improve Makefile by cleaning it up
• use the latest available target platform instead of hardcoding W11 22H2

Nothing about the functionality has changed in this PR (unless you include the Makefile), it's mostly laying the groundwork for a better organization so it's easier for me to later abstract for different platforms and GUI toolkits.

Sidenote: I am not exactly sure where to place the Frontend.hpp, which is why it's currently sitting awkwardly in src/discord. Perhaps a src/ui would make more sense, with some abstractions for buttons, text areas etc.

[iProgramMC]

I'm sorry, I don't know if I can accept this PR currently. This PR is a significant change and we haven't discussed any of these specific changes in the Discord server.

[iProgramMC]

Especially I disagree with the dismantling of src/discord. (src/discord looks to have been mostly just moved into src/core, at first glance I thought this PR would split it into multiple directories)

I believe it should be extremely clear which parts are meant to be cross-platform (specifically src/discord) and which are not (specifically src/windows)

[iProgramMC]

Actually this PR isn't that bad. but I would've appreciated a heads-up discussion before you went through with it.

Also please move src/discord/Frontend.hpp to src/core/Frontend.hpp so we can have just one directory again (src/core)

[pascalecu]

@iProgramMC are the changes good now?

[iProgramMC]

Other than these comments everything else looks good.

[iProgramMC]

BTW, I have actually been thinking to do a two-way merge with my Purplecord project in order to create a new library that both DiscordMessenger and Purplecord to use. But this is for later.

[iProgramMC]

Perhaps a src/ui would make more sense, with some abstractions for buttons, text areas etc.

The UI is platform specific. There will be no abstractions over the platform to create a cross-platform interface.

[iProgramMC]

Can you please rebase with master to fix the "entire file changed" shenanigans? Turns out they were caused by line endings that weren't normalized to LF.

[pascalecu]

What the... this is weird.

[iProgramMC]

wtf

[iProgramMC]

211.diff.txt
I saved the diff if you can't figure out how to recover your changes from git reflog.