[Feature Request] Support schedule search attribute update #629

Describe the solution you'd like

See temporalio/features#512. Need schedule search attribute support for schedule update. Depends on temporalio/sdk-go#1561. Specifically, we need to add schedule update support for the already existing --schedule-search-attribute flag. If any are present, replace entire existing search attribute collection. Setting one to null of course removes it (may need test to confirm. Also add a --remove-schedule-search-attributes that removes all search attributes (i.e. empty list) and is mutually exclusive with --schedule-search-attribute.