Bigtable: Request for Query#fromProto in models.Query #4260
Description
It would be nice to have Query.fromProto() for v2.models.Query to be able to convert to/from ReadRowsRequest.java.
As of now in TemplateUtil.java, we are using ValueProvider for ReadRowsRequst, but once migrating to Query, we wouldn't be able to create Query in TemplateUtis#RequestValueProvider#get as tableId will not be available until the latter part of the execution.
Related refactoring PR: googleapis/java-bigtable-hbase#2025