The previous naming was based on the input-device capability names from
libinput.
With code that uses the libinput_tablet_tool and mapping into tablet-v2,
this is confusing, so the name is changed to follow the names used in
the protocol.
A structs throughout the code use implementation specific free
functions.
When those functions are not used, they simply call free() on their
data, but this leaves around wl_signals linked into listeners.
When those listeners try to remove themself from the list, they write
into the now free memory.
This commit adds calls to remove the signals from those lists, so the
listeners can safely call wl_list_remove