Add OPeNDAP checks for granules

[jenny-m-wood]

Is this a new check? Please describe the check and the field.
Check: Check to see if OPeNDAP links are provided in the URL granule fields.
Fields: OnlineResources/OnlineResource/URL (echo-g) and RelatedURLs/URL (umm-g)

Describe the checks in steps

1. Check to see if "opendap" is present in the URL fields above
2. If not, check fails
3. Output message: Recommend providing an OPeNDAP link for this granule