#1253 Disable password-protected messages when FES is not used

[sosnovsky]

This PR enables password-protected messages only when FES is used

close #1253

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Tests (delete all except exactly one):

• Tests added or updated

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To be filled by reviewers

I have reviewed that this PR... (tick whichever items you personally focused on during this review):

• addresses the issue it closes (if any)
• code is readable and understandable
• is accompanied with tests, or tests are not needed
• is free of vulnerabilities
• is documented clearly and usefully, or doesn't need documentation

[sosnovsky]

I think that after finishing and merging #1331 we should also update EnterpriseServerApi to have email property (which will be passed from AppContextWithUser), so we don't need to pass it manually for every method.
Then we'll be able to fetch fesUrl only once and store result locally, while currently it's fetched for each request.

[sosnovsky]

@tomholub I have 2 remaining tasks - #1327 from 0.8.0 milestone and #1120 from 0.9.0
Should I also take some other tasks from 0.8.0 like #953 or #954 ?