add monitor block height mertics

[FineKe]

• 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 tests

• Updated relevant documentation (docs/)

• Added a relevant changelog entry to the Unreleased section in CHANGELOG.md

• Reviewed Files changed in the github PR explorer

---

For Admin Use:

• Added appropriate labels to PR (ex. wip, ready-for-review, docs)
• Reviewers Assigned
• Squashed all commits, uses message "Merge PR #XYZ: [title]" (coding standards)

[codecov-commenter]

Codecov Report

Merging #176 (fe462d8) into dev (8306798) will not change coverage.
The diff coverage is n/a.

❗ Current head fe462d8 differs from pull request most recent head 80fa5c9. Consider uploading reports for the commit 80fa5c9 to get more accurate results

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@@           Coverage Diff           @@
##              dev     #176   +/-   ##
=======================================
  Coverage   34.53%   34.53%           
=======================================
  Files         429      429           
  Lines       44762    44762           
=======================================
  Hits        15457    15457           
  Misses      28156    28156           
  Partials     1149     1149