Make a method to return or allocate the serial for a global.
When the global is unregistered, a new serial is calculated.
Place the serial in the object info and the global info.
Mark some structures, arrays static/const at various places.
In some cases this prevents unnecessary initialization
when a function is entered.
All in all, the text segments across all shared
libraries are reduced by about 2 KiB. However,
the total size increases by about 2 KiB as well.
This also brings the advantage that all tools, examples, modules, components
can also be compiled standalone out-of-tree using libpipewire from the system
Just like the real free() we should just ignore a NULL pointer, makes the
caller code easier for those instances where properties are optional.
Patch generated with concinelle with a few manual fixes.
First set the properties in the object itself and then copy them
over to the global. This ensure that the global properties are
also in the object and makes code a bit cleaner.
It also make it possible to use the global id to make the property
values unique, if we want to later .
