Install a pkg-config file during installation

[thilinarmtb]

Todo

• Update exec_prefix properly in the generated thapi.pc

[thilinarmtb]

@TApplencourt : Let me know if I am missing anything.

[TApplencourt]

Amazing! Should we change the test to use this? Or we are good they don't require that?
(I guess if not, we should add one test who use it :'D export PKG_CONFIG_PATH=/path/to/pkgconfig:$PKG_CONFIG_PATH and then

pkg-config --modversion mylib

But I guess the problem right now is that we don't have a lib at all : )

Libs: -L${libdir} -lThapi

So maybe in the PR just add modversion and then for the start-stop we can also modify the pkgconfig to add -L and -I?

[thilinarmtb]

Amazing! Should we change the test to use this? Or we are good they don't require that? (I guess if not, we should add one test who use it :'D export PKG_CONFIG_PATH=/path/to/pkgconfig:$PKG_CONFIG_PATH and then

pkg-config --modversion mylib

But I guess the problem right now is that we don't have a lib at all : )

Libs: -L${libdir} -lThapi

So maybe in the PR just add modversion and then for the start-stop we can also modify the pkgconfig to add -L and -I?

That was exactly what I was thinking.