make mk_attr_id part of ParseSess

[SparrowLii]

Updates #48685

The current mk_attr_id uses the AtomicU32 type, which is not very efficient and adds a lot of lock contention in a parallel environment.

This PR refers to the task list in #48685, uses mk_attr_id as a method of the AttrIdGenerator struct, and adds a new field attr_id_generator to ParseSess.

AttrIdGenerator uses the WorkerLocal, which has two advantages: 1. Cell is more efficient than AtomicU32, and does not increase any lock contention. 2. We put the index of the work thread in the first few bits of the generated AttrId, so that the AttrId generated in different threads can be easily guaranteed to be unique.

cc @cjgillot