Replace whitespace with underscores in benchmark plot/table version labels and file names

[yantosca]

Name and Institution (Required)

Name: Bob Yantosca
Institution: Harvard + GCST

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New GCPy feature or discussion

We propose replacing spaces and tabs with "_" characters in benchmark plot and table file names and version strings. Currently, it is possible to specify a version string with spaces, e.g.:

data:
  ref:
    gcc:
      version: gcc 14.2.0 rc 0
      ...
    gchp:
      version: gchp 14.2.0 rc 0
  ...
  dev:
    gcc:
      version: gcc 14.2.0 rc 2
      ...
    gchp:
      version: gchp 14.2.0 rc 2
       ...

and this would result in several file names for benchmark plots and tables having spaces in them.

[yantosca]

NOTE: PR #319 contains a new function named replace_whitespace that will strip whitespace from labels and file names. It has been applied to some of the newer benchmark scripts but needs to be applied to all benchmark scripts.