WLCS 1.3.0 Release

Notable changes:

• Check Cursor movement is not propagating to clients correctly when zwp_relative_pointer_manager_v1 is enabled
• Support getting the latest serial sent from the compositor (useful for popup grabs, and possibly other things in the future). Adding wl_keyboard makes sure new surfaces have a serial once they're focused, and provides access to keyboard focus
• Test that correct input event is used for interactive move
• Fix FindGtestGmock.cmake for new cmake (Fixes the build on Alpine Linux)
• Test that layer surfaces are correctly reconfigured
• Add tests for popup done event
• Test surfaces get enter/leave events
• Test version 2 and 3 features of zwlr_layer_shell_v1
• Destroy subsurfaces
• Show surface type names in paramaterized touch tests