[Task]: Make it possible to add, view or delete soft-blocks in the admin

[diox]

Description

Depends on #15012

Make it possible to add, view and delete soft-blocks in the admin, with logging about the change.

This is unlikely to be the main way to add or edit soft-blocks in production (reviewer integration should be added later), but this is needed for testing purposes and convenience for edge-cases where an admin might need to quickly add/delete a soft-block.

Acceptance Criteria

Milestones/checkpoints

Beta Give feedback

1. It should be possible to add a soft-block through the admin
2. It should be possible to delete soft-blocks through the admin
3. The admin should expose whether or not a given version in a block is soft or hard-blocked

Checks

• If the issue is ready to work on, I have removed the "needs:info" label.
• If I have identified that the work is specific to a repository, I have removed "repository:addons-server" or "repository:addons-frontend"

┆Issue is synchronized with this Jira Task

[ioanarusiczki]

• filed the followups after yesterday's checks on dev
• checked the dual sign-off on stage for 2 versions on https://reviewers.addons.allizom.org/en-US/reviewers/review/1004832 (confirming that at approval the block type cannot be modified)
• unblocked 2 versions on -dev -> showed up https://remote-settings-dev.allizom.org/v1/buckets/blocklists/collections/addons-bloomfilters/records
• in discussion on slack about stage and the tests made today (yesterday the blocked add-on showed up in stash)
  no problems with generation of bloomfilters for yesterday for {5e4f3038-b8c4-4163-84bb-7b21af1dd20a}

The ones below did not show up on https://firefox.settings.services.allizom.org/v1/buckets/blocklists/collections/addons-bloomfilters/records

https://addons.allizom.org/en-US/firefox/addon/stats-on-stage-5/versions/
https://addons.allizom.org/en-US/firefox/addon/one-blocked-one-restricted/
https://addons.allizom.org/en-US/firefox/addon/a-restricted/

[ioanarusiczki]

Today's test results on dev

• blocked versions showed up in stash and were blocked in the browser
  

• restricted versions unblocked did not show up in stash (so far expected)

On stage

• installed and hard blocked versions showed up in stash and have been blocked in the browser
• restricted versions are not present in stash and continue to be available in about:addons
• deleted hard-blocked versions are all present in stash