working on mmCIF encoder

package.json

src/mol-io/writer/cif.ts

src/mol-io/writer/cif/encoder.ts

src/mol-io/writer/cif/encoder/binary.ts

src/mol-io/writer/cif/encoder/text.ts

src/mol-io/writer/cif/filter.ts

src/mol-model/structure/export/mmcif.ts

src/mol-model/structure/structure/structure.ts