fix: fmod vars & whitespace trim pattern

[vladdoster]

Description

• use string pattern and move whitespace trim as variable
• make fmod variables local to remove warning messages

How Has This Been Tested?

Types of changes

• [ ] Breaking change (fix or feature that would cause existing functionality to change)
• [X] Bug fix (non-breaking change which fixes an issue)
• [ ] Documentation change
• [ ] New feature (non-breaking change which adds functionality)

Checklist:

• [ ] All new and existing tests passed.
• [ ] I have added tests to cover my changes.
• [X] I have updated the documentation accordingly.

[vladdoster]

before

/.local/share/zinit/plugins/zdharma-continuum---zinit-annex-bin-gem-node test*
MDN-X5J9PHV9NQ ᐳ zi delete -y fmod-demo; foobar(){ +zi-log -n '{m} foobar function'; pwd; }
zi for \
    as'null' \
    fmod'cgn:foobar' \
    id-as'fmod-demo' \
  @zdharma-continuum/null
==> Uninstalled fmod-demo

Downloading zdharma-continuum/null… (at label: fmod-demo…)
Cloning into '/Users/e109082/.local/share/zinit/plugins/fmod-demo'...
⠙ ███████████ OBJ: 100, PACK: 16/16, COMPR: 100%, REC: 100%, RES: 100%
za-bgn-atload-handler:140: scalar parameter set_node_path created globally in function za-bgn-atload-handler
za-bgn-atload-handler:140: scalar parameter set_virtualenv created globally in function za-bgn-atload-handler
za-bgn-atload-handler:140: scalar parameter set_cwd created globally in function za-bgn-atload-handler
za-bgn-atload-handler:140: scalar parameter use_all_null created globally in function za-bgn-atload-handler
za-bgn-atload-handler:140: scalar parameter use_err_null created globally in function za-bgn-atload-handler

after

zi delete -y fmod-demo; foobar(){ +zi-log -n '{m} foobar function'; pwd; }
zi for \
    as'null' \
    fmod'cgn:foobar' \
    id-as'fmod-demo' \
  @zdharma-continuum/null
==> Uninstalled fmod-demo

Downloading zdharma-continuum/null… (at label: fmod-demo…)
Cloning into '/Users/e109082/.local/share/zinit/plugins/fmod-demo'...
⠙ ███████████ OBJ: 100, PACK: 16/16, COMPR: 100%, REC: 100%, RES: 100%

[vladdoster]

Closed in favor of #32.