This brings together the two libraries back into one now that the whole
design is pretty well sorted out. They depend on roughly the same libraries
anyway and it's way easier of the single library can both read and write
the capture files (along with bringing in libsysprof-capture symbols in
a single place).
This removes -Dagent and just uses -Dtools as it only affects sysprof-cli
and sysprof-agent. We still need to patch sysprof-cli for recent changes
as we did for sysprof-agent though.
Additionally, we haven't used the v2 service in forever, so drop that as
I can't imagine anyone has been using it.
This also builds the agent statically with libsysprof_static_dep since
we'd need that to avoid installing libsysprof when that isn't wanted.
It also ensures the LD_PRELOAD libraries are installed for use by the
agent.
This is all aimed at making it so that sysprof can be built as a
subproject within GLib, with only `libsysprof-capture-4.a` being
produced as output.
Signed-off-by: Philip Withnall <withnall@endlessm.com>