gh-92936: update `http.cookies` docs post GH-113663 (#137566)

* add versionchanged and example with quotes in cookie value

* update whatsnew with http.cookies change

* Update Doc/library/http.cookies.rst

Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>

* Update Doc/whatsnew/3.15.rst

Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>

* spelling, quote

* demonstrate json

* Update Doc/library/http.cookies.rst

Co-authored-by: Senthil Kumaran <senthil@python.org>

* Apply suggestions from code review

Co-authored-by: Adam Turner <9087854+AA-Turner@users.noreply.github.com>

* shorter description

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Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>
Co-authored-by: Senthil Kumaran <senthil@python.org>
Co-authored-by: Adam Turner <9087854+AA-Turner@users.noreply.github.com>