Expand options for outputting context

[Repiteo]

Bringing over this QOL from the Pikmin 2 repo. Context files now have these expanded capabilities:

• Can now be integrated into the buildsystem directly, allowing autogeneration of context for each individual file
• Define to ninja as implicitly created, so context can be swiftly removed via ninja -t cleandead if desired
• Given a dedicated file extension, both for ease of browsing in file explorer & to entirely remove from VSCode inspector

[Repiteo]

Testing locally on some of the repos that use this repo's formatting, and this doesn't seem to work as expected compared to Pikmin 2. Gonna try to get to the bottom of that

[encounter]

For the recent feature I added to objdiff, auto-creating a decomp.me scratch, I implemented this same thing but slightly differently. Mainly: context generation are separate rules, and always available, but not built by default. I can see why it's useful to generate all of them at once, so maybe I can implement a ninja context step to do so

[Repiteo]

@ribbanya Having tried the alternative locally, I disagree with swapping the extension. With this implementation, it's making context for every compiled file, so that bloat would add up extremely fast. Because excluding it explicitly isn't as straightforward as I'd like, and considering the main use-case is to be taken to decomp.me, I'm fine with leaving it as-is in a metadata-esque way

However, one alternative would be still compiling all the context, but in a designated location. It would output similar to how .obj files are created in their own folders in a way that mirrors the scripts being compiled, just in a separate location. Excluding an entire directory would be significantly easier than dealing with wildcards

[ribbanya]

Yeah that makes sense. In that case I would prefer a layout of build/ctx/dolphin/gx/GXInit.c mirroring the source tree. Maybe build/ctx/src/... if you want to allow for multiple context root directories.

[encounter]

Thanks for the work on this, closing because context generation and objdiff decomp.me integration is available on main.