Add support for the Buhid and Tagbanwa scripts (bug#55610)

Add support for the Buhid and Tagbanwa scripts (bug#55610)

* lisp/language/philippine.el ("Buhid"): New language environment.
("Tagbanwa"): New language environment.
Add input methods for Buhid and Tagbanwa.
Add sample text for Tagbanwa.
* lisp/international/fontset.el (script-representative-chars)
(setup-default-fontset): Support Buhid and Tagbanwa.
* lisp/leim/quail/philippine.el ("buhid"): New input method.
("tagbanwa"): New input method.

* etc/HELLO: Add a Tagbanwa greeting.
* etc/NEWS: Announce the new language environments and their
input methods.