Meson refactor: collect modules in dict and centralize config

[thestr4ng3r]

Your checklist for this pull request

• I've read the guidelines for contributing to this repository
• I made sure to follow the project's coding style
• I've documented or updated the documentation of every function and struct this PR changes. If not so I've explained why.
• I've added tests that prove my fix is effective or that my feature works (if possible)
• I've updated the rizin book with the relevant information (if needed)

Detailed description

Duplicated code for pkg-config and cmake configuration is avoided by
letting every rizin module register itself in a global dictionary
called "modules" which is then iterated in one place to perform any
shared logic, inspired by how qemu handles multiple targets in its meson
build system.

This is an almost pure refactor, so the resulting .pc/.cmake files
should be identical with the following exceptions:

• rz_reg.pc does not have plugindir anymore as rz_reg has no plugins.
• Some other modules have their dependencies in .pc files altered to be
  consistent with cmake.

Test plan

Compiling should work and installed lib/cmake and lib/pkgconfig contents should be identical to before except where noted above.