Refactored existing gdb-remote qProcessInfo tests into separate python file.

I'm about to add some more qProcessInfo tests so I wanted to first pull them out
of the monolithic TestLldbGdbServer test case class.

Related to http://llvm.org/bugs/show_bug.cgi?id=20755


git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@216465 91177308-0d34-0410-b5e6-96231b3b80d8