Add some representative nodes.

Add some representative nodes.
(U+3690): Apply new conventions for glyph granularity.
(U+3691): Likewise.
(U+3693): Likewise.
(U+5941): Likewise.
(U+5951): Likewise.
(U+5952): Likewise.
(U+5955): Likewise.
(U-00021619): Likewise.
(mother of M-05925): Unify A-M-05925.
(U-00021636): Apply new conventions for glyph granularity.
(U+595C): Likewise.
(U+595E): Likewise.
(IU+21639): Unify GT-07492 and GT-K08253.
(U-0002162C): Apply new conventions for glyph granularity.
(U-00021643): Likewise.
(U+5960): Likewise.
(U+596A): Likewise.
(U+596E): Likewise.
(U+596F): Likewise.