libsysprof-ui: land new UI design

This comprises a massive rewrite of the UI for browsing captures. We use
the SysprofAid class to scan capture files for content and then auto-
matically add visualizers and details pages.

To avoid breaking things incrementally, we just land this as a very large
commit. Not necessarily ideal, but given the amount of stuff that could
break, this is easier.

As part of this process, we're removing a lot of the surface API so that
we can limit how much we need to maintain in terms of ABI.

src/tests/meson.build

@@ -61,7 +61,8 @@ if get_option('enable_gtk')
     dependencies: test_ui_deps,
   )
 
-  test_zoom = executable('test-zoom', 'test-zoom.c',
+  test_zoom = executable('test-zoom',
+    ['test-zoom.c', '../libsysprof-ui/sysprof-zoom-manager.c'],
           c_args: test_cflags,
     dependencies: test_ui_deps,
   )