feat: Use loadfile that allows reading Config from local file or uri

[brian-intel]

close #553

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PR Checklist

Please check if your PR fulfills the following requirements:

• I am not introducing a breaking change (if you are, flag in conventional commit message with BREAKING CHANGE: describing the break)
• I am not introducing a new dependency (add notes below if you are)
• I have added unit tests for the new feature or bug fix (if not, why?)
• I have fully tested (add details below) this the new feature or bug fix (if not, why?)
• I have opened a PR for the related docs change (if not, why?)

Testing Instructions

• add EDGEX_CONFIG_FILE= to any service
• start edgex in secure or no-secure mode
• Modified service should get config from the remote location instead of the local copy.

New Dependency Instructions (If applicable)

[codecov-commenter]

Codecov Report

Merging #558 (078d553) into main (d15a138) will increase coverage by 0.30%.
The diff coverage is 72.22%.

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@@            Coverage Diff             @@
##             main     #558      +/-   ##
==========================================
+ Coverage   57.84%   58.15%   +0.30%     
==========================================
  Files          28       28              
  Lines        2275     2282       +7     
==========================================
+ Hits         1316     1327      +11     
+ Misses        871      869       -2     
+ Partials       88       86       -2     

Impacted Files	Coverage Δ
bootstrap/config/config.go	31.61% <72.22%> (+0.83%)	⬆️

... and 1 file with indirect coverage changes

[jim-wang-intel]

some improvement suggestions

[lenny-goodell]

LGTM

[ejlee3]

Left one comment, but LGTM