Create warning banner on non-prod IMS web clients

[srabraham]

Clubhouse has one of these, and it's a good idea to help users recognize prod from nonprod.

[srabraham]

@wsanchez What do you think? I'll need a bit of help from you to make this happen, since the prod server would need to be able to identify itself as such.

e.g. if you're on board with this, could you add an imsd.conf entry/env variable like "IMS_ENVIRONMENT=prod" or similar? No rush on this.

I'd then add code here to read that value

ranger-ims-server/src/ims/config/_config.py

Line 220 in 30c6cfd

[srabraham]

Talking with @mikeburg, he's setting up an environment variable for this in AWS. I'll set up the server to look for this

IMS_DEPLOYMENT=Staging
IMS_DEPLOYMENT=Prod
IMS_DEPLOYMENT=Training

[srabraham]

I made another little tweak here: #1397