Fix repeating fields within repeating groups by changing regex depending on context

[daggerhart]

Fixes #1035 and #348. Possibly related to #712 and others.

Changes proposed in this pull request

• Pass the group boolean into cmb.elReplacements so it can know which index to replace for new Name and new IDs.

  • If the new replacements are for a group, use a regex that won't match a field's attributes.
  • If the new replacements are not for a group, use a regex that finds matches at the end of the field attribute strings, avoiding the group-level values within those attributes.

• When a new group is added, fix the name and ID attributes on the hidden .empty-rows so that the next "Add Row" has the correct attributes.

[jtsternberg]

Nice, thanks!