This migrates all remaining uses of cImport (and addTranslateC for good
measure) to using translate-c for C translation, ensuring that we are
ready for when cImport is removed from the language, and also that all
sources of C translation are using the same snapshot of the external
package (when can then be updated when we need to fix something).
A couple of notes:
* A few options have been added to support the new translations, namely
the ability to link libraries (passed through to linkLibrary on the
Translator side) and whether or not to initialize default values
(looks like cImport did this without a way to control it, but
translate-c does not do it by default).
* Using the new library linking option actually simplifies the process
of translating a number of the C packages as we have been shipping the
necessary headers for these packages already with the applicable
libraries. For some of the more complex translation processes though,
we still include the appropriate directories directly.
Fixes#10406
ImGui_ImplOpenGL3_Shutdown() calls imgl3wShutdown() which dlcloses the
GL library handles but does not zero out the imgl3w function pointer
table (imgl3wProcs). When a GLArea is re-realized (e.g. during
reparenting), ImGui_ImplOpenGL3_Init() calls ImGui_ImplOpenGL3_InitLoader()
which checks "if (glGetIntegerv == nullptr)". Since the stale pointers
are non-null, it skips re-initialization. The next GL call through a
dangling function pointer causes a SIGSEGV.
Fix this by introducing ImGui_ImplOpenGL3_ShutdownWithLoaderCleanup()
which calls the normal shutdown and then zeroes the imgl3wProcs table,
forcing the next Init to reload GL function pointers via imgl3wInit().
Also properly destroy the ImGui context and reset widget state in
glAreaUnrealize so re-realize starts clean. This was extra but was
probably leaking memory.
