feat: Add shared dictionary management APIs (#44750)

* Add bare-bones GetSharedDictionaryUsageInfo

* Add GetSharedDictionaryInfo()

* Improve API, use isolation keys

* Add documentation

* Update docs/api/session.md

Co-authored-by: John Kleinschmidt <kleinschmidtorama@gmail.com>

* Update shell/browser/api/electron_api_session.cc

Co-authored-by: Samuel Attard <samuel.r.attard@gmail.com>

* Add tests

* Implement feedback <3

* Improve tests

* chore: lint

* docs: add note about clearing cache in ses.clearData

---------

Co-authored-by: John Kleinschmidt <kleinschmidtorama@gmail.com>
Co-authored-by: Samuel Attard <samuel.r.attard@gmail.com>
Co-authored-by: alice <alice@makenotion.com>