auth: Update AccountRetriever

[alexanderbez]

Description

The AccountRetriever now has no dependencies and solely relies on the client.Context provided as an argument.

closes: #6985

---

Before we can merge this PR, please make sure that all the following items have been
checked off. If any of the checklist items are not applicable, please leave them but
write a little note why.

• Targeted PR against correct branch (see CONTRIBUTING.md)
• Linked to Github issue with discussion and accepted design OR link to spec that describes this work.
• Code follows the module structure standards.
• Wrote unit and integration tests
• Updated relevant documentation (docs/) or specification (x/<module>/spec/)
• Added relevant godoc comments.
• Added a relevant changelog entry to the Unreleased section in CHANGELOG.md
• Re-reviewed Files changed in the Github PR explorer
• Review Codecov Report in the comment section below once CI passes

[codecov]

Codecov Report

Merging #7006 into master will decrease coverage by 0.97%.
The diff coverage is 91.30%.

@@            Coverage Diff             @@
##           master    #7006      +/-   ##
==========================================
- Coverage   61.95%   60.98%   -0.98%     
==========================================
  Files         520      380     -140     
  Lines       32036    24778    -7258     
==========================================
- Hits        19848    15110    -4738     
+ Misses      10559     8476    -2083     
+ Partials     1629     1192     -437     

[amaury1093]

LGTM 👍 . Just need to remove all references to NodeQuerier. Could you also change AccountRetriever's signature in ADR020?

Putting a red cross for now to avoid automerge.

[amaury1093]

lgtm