client/keys/parse.go: honor config changes

[boz]

keys parse uses the global configuration before
before client applications have had a chance to
apply their settings.

This change adds a GetSealedConfig() helper
that waits for the config to be sealed before
returning it.

fixes #5091
addresses #5283

[auto-comment]

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[codecov]

Codecov Report

Merging #6172 into master will decrease coverage by 0.00%.
The diff coverage is 65.71%.

@@            Coverage Diff             @@
##           master    #6172      +/-   ##
==========================================
- Coverage   54.79%   54.79%   -0.01%     
==========================================
  Files         443      443              
  Lines       26704    26729      +25     
==========================================
+ Hits        14633    14645      +12     
- Misses      11032    11044      +12     
- Partials     1039     1040       +1     

[alessio]

Approved. Thanks @boz, appreciated!