Boost: add conditional variants

[hainest]

Fixes #1486 Fixes #11467 Closes #31237 Fixes #30663

TODO

• [x] Remove all_libs. I think this can be done with something like [v.lib for v in self.variants if v.enabled] and then call self.libs() in install (at for lib in Boost.all_libs: around line 692).
• [x] Check version ranges for the other variants
• [x] boost@master does not build on develop. I believe this is due to the if not with_libs check in install. I have not verified this yet. I will post build error messages later.
• [x] There are many b2 properties/features we don't support. See #30496

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