Add "scroll to activity" to activity directive table context menu (#1433)

[ivydeliz]

Resolves #1433

This one is my first substantial task so please check me I didn't do anything too crazy 😄

To test:

1. Open a Plan, go to the Activity Directives Table
2. Right Click on a single activity directive, you should see "Scroll to Activity"
3. Select a few items in the table, and right click, you should NOT see "Scroll to Activity"
4. In the Timeline Histogram select a smaller time range
5. From the Activity Directives Table, right click on activities at the start, middle and end of plan and click on "Scroll to Activity" in the context menu, it should scroll to show them if it is not visible, otherwise it just selects it in the timeline!

[ivydeliz]

@duranb ok i think i crushed it now, with unit tests and all! AND i handled the bounded case where the time range is bounded by maxTimeRange but should keep the same time range span, which it wasn't doing before, in the cases of the edges of the plan the time range span changed as you kept scrolling to activities, which was a bit funky.

[AaronPlave]

Any reason not to add this capability to the simulated activities table?

[ivydeliz]

@AaronPlave this task was just scoped to the activity directives. If we want to add it to the simulated activities table if we want to scroll to the start of the activity then the code would be pretty much the same, but it should be it's own task instead of adding more scope to this one.

[AaronPlave]

@AaronPlave this task was just scoped to the activity directives. If we want to add it to the simulated activities table if we want to scroll to the start of the activity then the code would be pretty much the same, but it should be it's own task instead of adding more scope to this one.

Sounds good, I'll make a ticket for that. #1553

[duranb]

lgtm!