bump react-router and react-router-dom to 5.3.4

[timgerstel]

This PR addresses Issue: [Link to Github issue within https://github.com/zowe/zlux/issues if any]

PR Type

• Bug fix
• Feature
• Other (Please indicate)

PR Checklist

• PR completes npm run preCommit without error
• Relevant Test cases have been added (Unit and or FVT)
• Relevant update to CHANGELOG.md
• PR from forked repo? Ensure Allow edits by maintaners is set.

[sonarcloud]

Quality Gate failed

Failed conditions
0.0% Coverage on New Code (required ≥ 80%)

See analysis details on SonarCloud

[1000TurquoisePogs]

The tests are broken by upgrades to the test libraries themselves and need to be updated.
For now I am merging as manual tests have shown things to be fine.
I am creating an issue in the zlux backlog about fixing this in the long run.