(A-BC-8866): New abstract node; unify A-BC-8CB8-itaiji-002.

(A-BC-8866): New abstract node; unify A-BC-8CB8-itaiji-002.
(BC-8866): Add `<-denotational' for A-BC-8866; unify
BC-8CB8-itaiji-002.
(U-00022999): Apply new conventions for glyph granularity.
(U+6216): Add `<-denotational@usage' for BUCS+6216; add
`sound@ja/on/{kan|go}'; unify DJT-03617; add some relations for other
characters.
(A-U+22999-itaiji-002): New abstract node.
(U+22999-itaiji-002): New character; use `<-denotational' for
A-U+22999-itaiji-002.
(A-cgnU+229C4): New abstract node.
(U+621C): Add `<-denotational' for A-cgnU+229C4; add
`<-denotational@component' for A-cgnU+21333; modify structure;
preserve the previous IDS as an apparent structure.
(U-000229C4): New character; use `<-denotational' for A-cgnU+229C4.
(U-00022A0A): Apply new conventions for glyph granularity.
(U+39BD): Likewise.
(BUCS+6216): New abstract node; unify A2-DJT-03617.