Modify related terms to work with Regions of Interest

[baskaufs]

The following term changes were recommended by the Maintenance Group in their 2021-06-08 meeting to make existing terms applicable to the proposed Regions of Interest (#206). Their adoption would be contingent on acceptance of other proposals as noted. Definitions and usage are normative, so these changes all require public comment and Executive Committee approval.

Proposed changes:

ac:freqHigh
Change definition from "The highest frequency of the phenomena reflected in the multimedia item." to "The highest frequency of the phenomena reflected in the multimedia item or Region of Interest.".
Change notes from "... If dwc:scientificName is specified, these frequency bounds..." to "... If dwc:scientificName is specified and if applied to the entire multimedia item, these frequency bounds..."
Contingent on approval of #206.

ac:freqLow
Change definition from "The lowest frequency of the phenomena reflected in the multimedia item." to "The lowest frequency of the phenomena reflected in the multimedia item or Region of Interest.".
Change notes from "... If dwc:scientificName is specified, these frequency bounds..." to "... If dwc:scientificName is specified and if applied to the entire multimedia item, these frequency bounds..."
Contingent on approval of #206.

xmp:CreateDate
Add to Usage: "When applied to a media resource with temporal extent such as audio or video, this property indicates the startTime of the recording."
Contingent on approval of #208.

[baskaufs]

Ratified by the Executive on 2021-10-05 and implemented in tdwg/rs.tdwg.org#79 and #212