7469 request access feedback

[sekmiller]

What this PR does / why we need it: Adds feedback to the user when they request access to a restricted file.

• A Success Banner message when there's a valid access request made
• An info tag added the the files table for any active request which will remain until the request is acted upon by the admin
• The general Request Access button will be removed when there are no more files that can be requested (all are public or all have been granted access or all have pending requests or any combination of the above)
• A warning message will be displayed if a request is made on a file that is already public or has an active request (this is possible if there is still a file or files for which a valid request may be made alongside others that are public, etc.)

Which issue(s) this PR closes:

Closes #7469 People requesting access to a file need visible feedback when a request is sent

Special notes for your reviewer:

Suggestions on how to test this:

Does this PR introduce a user interface change? If mockups are available, please link/include them here:

Is there a release notes update needed for this change?:

Additional documentation:

[pdurbin]

Overall, I think the code looks fine. I'm sending back, however, because I noticed some strange behavior.

Step 1. From the file table, click the access button, then "Request Access"

Step 2. Observe a spinner and no change to the file table

Step 3. Later, if you refresh the page, you'll see that the access request actually went through. The problem is the lack of feedback in Step 2.

[sekmiller]

I missed adding the update to the single file request button. It should be ok now.

[coveralls]

Coverage decreased (-0.001%) to 18.918% when pulling 4253780 on 7469-request-access-feedback into 6fa131f on develop.

[scolapasta]

@sekmiller @djbrooke approved, but it says Meging is blocked once changes are approved. Does @pdurbin need to do the actual (re) approval? I do see an option to "dismiss review" and could try that to see if that clears it.

[djbrooke]

@scolapasta yes, it's fine to dismiss the review in this case.

@pdurbin is out and I (re0 reviewed in his place