[DEFECT] Opt Path labels with a lot of underscores are illegible if too long

Thank you for the defect report

[X] I am using the latest version of RAVEN.
[X] I have read the Wiki.
[X] I have created a minimum, reproducible example that demonstrates the defect.

Defect Description

When using the optimization path plot, if the var names are too long the y-labels are not legible. Example from the HERON "optimization_settings" regression test: 1-opt_path_old

Steps to Reproduce

Run a RAVEN optimization script with an Outstreams node subtype OptPath, code example below from the HERON optimization settings regression test:

<OutStreams>
    <Plot name="opt_path" subType="OptPath">
      <source>opt_soln</source>
      <vars>GRO_capacities, VaR_0.05_NPV</vars>
    </Plot>
  </OutStreams>

A current RAVEN example exists in the workshop documentation

Expected Behavior

Y-labels should be legible even if names are long. Particularly, HERON uses a lot of strings joined by underscores. It would be good to split the strings by the underscores.

Screenshots and Input Files

No response

OS

Windows

OS Version

No response

Dependency Manager

PIP

For Change Control Board: Issue Review

[x] Is it tagged with a type: defect or task?
[x] Is it tagged with a priority: critical, normal or minor?
[x] If it will impact requirements or requirements tests, is it tagged with requirements?
[x] If it is a defect, can it cause wrong results for users? If so an email needs to be sent to the users.
[x] Is a rationale provided? (Such as explaining why the improvement is needed or why current code is wrong.)

For Change Control Board: Issue Closure

[x] If the issue is a defect, is the defect fixed?
[x] If the issue is a defect, is the defect tested for in the regression test system? (If not explain why not.)
[x] If the issue can impact users, has an email to the users group been written (the email should specify if the defect impacts stable or master)?
[x] If the issue is a defect, does it impact the latest release branch? If yes, is there any issue tagged with release (create if needed)?
[x] If the issue is being closed without a pull request, has an explanation of why it is being closed been provided?

idaholab / raven