Enable full pagination support for the metadata OS Locator queries

[dwedul-figure]

Description

Refactor the metadata module's OSAllLocators and OSLocatorsByURIRequest queries to fully support the pagination features.

closes: #401
closes: #402

---

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.
• 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 #470 (6f8f9b5) into main (7ad9b0e) will increase coverage by 0.12%.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##             main     #470      +/-   ##
==========================================
+ Coverage   54.02%   54.14%   +0.12%     
==========================================
  Files         149      149              
  Lines       19159    19116      -43     
==========================================
  Hits        10351    10351              
+ Misses       8021     7978      -43     
  Partials      787      787              

Impacted Files	Coverage Δ
x/metadata/keeper/query_server.go	26.40% <0.00%> (+1.17%)	⬆️