Add deprecation messages to security managers APIs

[just-joshing]

The organization security manager role REST APIs are being sunset (https://gh.io/security-managers-rest-api-sunset) in favor of the organization roles REST APIs.

This change adds deprecation messages to tell consumers which client operations to use instead going forward.

[just-joshing]

I had previously tried updating these operations instead to use the replacement client methods under-the-hood but got feedback to go the deprecation route instead.

[stevehipwell]

LGTM

[gmlewis]

Thank you, @just-joshing and @stevehipwell !
LGTM.
Merging.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 92.22%. Comparing base (2b8c7fa) to head (9f0b14d).
Report is 217 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #3426      +/-   ##
==========================================
- Coverage   97.72%   92.22%   -5.51%     
==========================================
  Files         153      173      +20     
  Lines       13390    14937    +1547     
==========================================
+ Hits        13085    13775     +690     
- Misses        215     1068     +853     
- Partials       90       94       +4     

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