Two small form CJK characters for Chinese

[eggrobin]

See L2/23-284 Proposal to encode two small form CJK characters for Chinese and L2/24-012 Section 21).

See discussion of properties in https://github.com/unicode-org/properties/issues/233

[178-C27] Consensus: Accept the proposal to provisionally assign U+16FF2 CHINESE SMALL SIMPLIFIED ER and U+16FF3 CHINESE SMALL TRADITIONAL ER in the Ideographic Symbols and Punctuation block, based on document L2/23-284 (West & Chan) and Section 21 of document L2/24-012.