By moving got_serve_parse_command() from lib/serve.c into lib/dial.c as got_dial_parse_command(), we can significantly reduce the amount of symbols gitwrapper depends on indirectly. As a downside, gotsh now needs to link to dial.c. But it only uses the same parsing routine, and any other routines in dial.c would likely cause pledge violations in gotsh if used. No functional change.

These functions are used by 'got send' and 'got fetch' in order to open network connections to a server. Move them into new file lib/dial.c and declare relevant functions in got_dial.h and lib/got_lib_dial.h. No functional change.