Create fromProtobuf utility method in existing models

[rahulKQL]

**Please describe requested feature? **
User should be able to transform protobuf object into bigtable client's model object. Similar to:

java-bigtable/google-cloud-bigtable/src/main/java/com/google/cloud/bigtable/data/v2/models/Query.java

Lines 272 to 285 in 4374492

	/**
	* Wraps the protobuf {@link ReadRowsRequest}.
	*
	* <p>WARNING: Please note that the project id & instance id in the table name will be overwritten
	* by the configuration in the BigtableDataClient.
	*/
	public static Query fromProto(@Nonnull ReadRowsRequest request) {
	Preconditions.checkArgument(request != null, "ReadRowsRequest must not be null");
	Query query = new Query(NameUtil.extractTableIdFromTableName(request.getTableName()));
	query.builder = request.toBuilder();
	return query;
	}

Additional context
Discussed offline in the last meeting.