Schedule update search attributes

[THardy98]

What was changed

Allow schedules to update their search attributes.

1. Closes [Feature Request] Support schedule search attribute update #1475

2. How was this tested:
   Added integration test.

3. Any docs updates needed?
   Unsure

[mjameswh]

I'm wondering if we might be better not add support for legacy (non-typed) SA on Schedule Update. I mean, we supported those elsewhere because those APIs existed before, but Schedule Update didn't had that, so why add an API here that would be immediately considered as deprecated? WDYT?

[THardy98]

Yeah I think that's fair, no sense in permitting something that's deprecated. I'll continue to omit searchAttributes.

[THardy98]

Ah - this is why, the update handler:

  /**
   * Update the Schedule
   *
   * This function calls `.describe()`, provides the `Schedule` to the provided `updateFn`, and
   * sends the returned `UpdatedSchedule` to the Server to update the Schedule definition. Note that,
   * in the future, `updateFn` might be invoked multiple time, with identical or different input.
   */
  update<W extends Workflow = Workflow>(
    updateFn: (previous: ScheduleDescription) => ScheduleUpdateOptions<ScheduleOptionsStartWorkflowAction<W>>
  ): Promise<void>;

To update, the user supplies a function that takes a ScheduleDescription and returns ScheduleUpdateOptions. ScheduleDescription already has a searchAttributes field.

I forgot about this.

We can have this discrepancy to force users to use typed search attributes, but I don't think this will be obvious to users until they run into unexpected behavior (i.e. update searchAttributes from description but it doesn't actually do anything because it doesn't exist in update options).

I think I would prefer to have consistency between ScheduleDescription and the ScheduleUpdateOptions but am not fussy either way.

[mjameswh]

That makes sense. Let's keep it.