Optimize generate-sr-assets

[jonathanmos]

What does this PR do?

Optimize the runtime for generate-sr-assets and add some useful flags.

Flags are:
--help - print out details of supported flags.
--verbose - output useful information to the console during the run.
--path - specify explicitly the path the script should run on.
--followSymlinks - whether the script should follow symlinks while traversing - false by default.
--ignore - ignore certain patterns during the traversal. If no wildcard is provided then it assumes a folder name and ignores as a glob pattern:
e.g. 'legacy' -> '**/legacy/**'

Motivation

What inspired you to submit this pull request?

Additional Notes

Anything else we should know when reviewing?

Review checklist (to be filled by reviewers)

• Feature or bugfix MUST have appropriate tests
• Make sure you discussed the feature or bugfix with the maintaining team in an Issue
• Make sure each commit and the PR mention the Issue number (cf the CONTRIBUTING doc)
• If this PR is auto-generated, please make sure also to manually update the code related to the change

[cdn34dd]

Overall looks good