Researcher UI: clarify delete/archive/deactivate study options

**Description**

After deleting a study via the experimenter UI (Change State -> Delete), the study seems to be archived rather than deleted. The experimenter stays on the page for the deleted study, and both the banner message and Study State indicate that the study has been _archived_ (not deleted).

As a user this is confusing because you thought you just deleted the study. Since the user is still on the study page, they may think that the study was not actually deleted and try again, but clicking Change State reveals an empty drop-down menu.

Navigating to the My Studies section does show that the study has been appropriately removed/hidden.

https://user-images.githubusercontent.com/9041788/177880666-f6c5aa45-0f07-4998-a9e0-1fd96c554bf0.mov

It's also not clear to me what the "deactivate" option is supposed to do and how it differs from delete/archive, since the option label and help text for "deactivate" say that deactivating = archiving:
> "Deactivate (archive study - data collection is complete)"
>"This will archive the study..."

**How to reproduce**

On top level study page: Change State -> Delete (delete study and any data)

**Expected behavior**

If the "Delete" action should actually remove the study:
1. Researcher should not return to page for the study that was just deleted. Instead they should be sent somewhere sensible like the Manage Studies page.
2. Banner message should indicate that the study was successfully _deleted_ (not archived, as it currently says).
3. Study page should no longer be accessible after the study has been deleted.

Otherwise:
1. On the top level study page, under Change State, the "Delete" option should be renamed "Archive".
2. Change State label and help text for "Deactivate" should be changed to clarify how this option differs from "Archive".

**Additional context**

Study status options and descriptions: https://github.com/lookit/lookit-api/blob/573fdf7123062410c534aecaac41f77faa12f3f4/studies/workflow.py#L113-L135

This was also discussed in #208 (closed issue):
> Proposed changes to study state change names:
"Activate" -> "Start data collection"
"Pause" -> "Pause data collection"
"Submit" -> "Submit for review"
"Deactivate" -> ??? depends what this does exactly, but as is it reads as the opposite of "Activate" which is not true. From the standpoint of a typical researcher is this "Delete"? Is "archived" actually different from "deactivated"?

> Remaining todo:
Rename "deactivate" and other actions under "change state" for clarity

**Environment**

MacOS Monterey 12.4, Chrome

Read studies/workflow.py lines 113-135 and trace the researcher UI's Change State actions for Delete and Deactivate. Reproduce the state change, then clarify the distinct semantics and make the redirect, banner, study accessibility, labels, and help text consistently reflect the chosen behavior.

Written by the indexing model from the issue text.