feat: deprecate password file in favor of secrets

[iromli]

The changeset deprecate password files (sql_password, couchbase_password, couchbase_superuser_password) in favor of value from secrets.
For existing deployments, the password from any of password files mentioned previously is saved into secrets. Subsequent deployment may remove the password files safely.
For fresh deployments, there are additional scopes and attributes that can be used to specify password for SQL and Couchbase databases.

[codecov]

Codecov Report

Merging #150 (a1b854f) into master (2d5d61b) will decrease coverage by 0.28%.
The diff coverage is 90.00%.

❗ Current head a1b854f differs from pull request most recent head a2d3a16. Consider uploading reports for the commit a2d3a16 to get more accurate results

@@            Coverage Diff             @@
##           master     #150      +/-   ##
==========================================
- Coverage   68.80%   68.51%   -0.29%     
==========================================
  Files          29       29              
  Lines        1683     1674       -9     
==========================================
- Hits         1158     1147      -11     
- Misses        525      527       +2     

Flag	Coverage Δ
unittests	68.51% <90.00%> (-0.29%)	⬇️

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Impacted Files	Coverage Δ
jans-pycloudlib/jans/pycloudlib/utils.py	80.26% <ø> (-2.40%)	⬇️
jans-pycloudlib/jans/pycloudlib/persistence/sql.py	50.67% <87.50%> (+0.67%)	⬆️
...ycloudlib/jans/pycloudlib/persistence/couchbase.py	84.27% <91.66%> (+0.04%)	⬆️

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