message: link type tweaks
diff: @@ -11,7 +11,7 @@ import { LinkType } from '../../../types'
  import { findEntityIdByAsymId, findAtomIndexByLabelName } from '../util'
  import { Column } from 'mol-data/db'
  import { ModelPropertyDescriptor } from '../../../properties/custom';
  -import { mmCIF_Database } from 'mol-io/reader/cif/schema/mmcif';
  +import { mmCIF_Database, mmCIF_Schema } from 'mol-io/reader/cif/schema/mmcif';
  import { SortedArray } from 'mol-data/int';
  import { CifWriter } from 'mol-io/writer/cif'
  import { ElementIndex } from '../../../indexing';
  @@ -137,17 +137,7 @@ export namespace StructConn {
  partners: { residueIndex: number, atomIndex: ElementIndex, symmetry: string }[]
  }
  - type StructConnType =
  - | 'covale'
  - | 'covale_base'
  - | 'covale_phosphate'
  - | 'covale_sugar'
  - | 'disulf'
  - | 'hydrog'
  - | 'metalc'
  - | 'mismat'
  - | 'modres'
  - | 'saltbr'
  + type StructConnType = typeof mmCIF_Schema.struct_conn.conn_type_id.T
  export function attachFromMmCif(model: Model): boolean {
  if (model.customProperties.has(Descriptor)) return true;
  @@ -248,7 +238,7 @@ export namespace StructConn {
  case 'disulf': flags = LinkType.Flag.Covalent | LinkType.Flag.Sulfide; break;
  case 'hydrog': flags = LinkType.Flag.Hydrogen; break;
  case 'metalc': flags = LinkType.Flag.MetallicCoordination; break;
  - case 'saltbr': flags = LinkType.Flag.Ion; break;
  + case 'saltbr': flags = LinkType.Flag.Ionic; break;
  }
  entries.push({ rowIndex: i, flags, order, distance: pdbx_dist_value.value(i), partners });
  