Bar graphs should only get latest historical datum

[shefalijoshi]

Closes #7781

Describe your changes:

Since bar graphs only need the latest telemetry, set the size of historical request to 1

All Submissions:

• Have you followed the guidelines in our Contributing document?
• Have you checked to ensure there aren't other open Pull Requests for the same update/change?
• Is this a notable change that will require a special callout in the release notes? For example, will this break compatibility with existing APIs or projects that consume these plugins?

Author Checklist

• Changes address original issue?
• Tests included and/or updated with changes?
• Has this been smoke tested?
• Have you associated this PR with a type: label? Note: this is not necessarily the same as the original issue.
• Have you associated a milestone with this PR? Note: leave blank if unsure.
• Testing instructions included in associated issue OR is this a dependency/testcase change?

Reviewer Checklist

• Changes appear to address issue?
• Reviewer has tested changes by following the provided instructions?
• Changes appear not to be breaking changes?
• Appropriate automated tests included?
• Code style and in-line documentation are appropriate?

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 58.82%. Comparing base (de122b9) to head (8e87191).
Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #7811      +/-   ##
==========================================
- Coverage   59.18%   58.82%   -0.37%     
==========================================
  Files         675      675              
  Lines       27284    27284              
  Branches     2671     2671              
==========================================
- Hits        16149    16049     -100     
- Misses      11088    11187      +99     
- Partials       47       48       +1     

Flag	Coverage Δ
e2e-ci	61.77% <ø> (-0.01%)	⬇️
e2e-full	23.51% <ø> (-18.46%)	⬇️
unit	51.22% <ø> (-0.13%)	⬇️

Files with missing lines	Coverage Δ
src/plugins/charts/bar/BarGraphView.vue	67.64% <ø> (ø)

... and 13 files with indirect coverage changes

---

Continue to review full report in Codecov by Sentry.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update de122b9...8e87191. Read the comment docs.

[ozyx]

Just a couple minor comments and a question

[ozyx]

Running the e2e test 10x in a docker env that matches our CI environment demonstrates inherent flakiness due to the lack of determinate waits:

I think we should move this test to the openmct-yamcs side so we can test it against real network requests in addition to having deterministic wait conditions via waitForRequest()

[unlikelyzero]

Now that we have tests in the openmct-yamcs PR, let's remove the tests from this PR