Add more command-line customization for `SB()` and `Driver()` formats

[mdmintz]

Add more command-line customization for SB() and Driver() formats

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Eg. The ability to set a User-Agent from the command-line when it hasn't already been set directly in the script itself.
(Such as: python raw_sb.py --agent="My User Agent String")

[mdmintz]

This was resolved in 4.29.9 - https://github.com/seleniumbase/SeleniumBase/releases/tag/v4.29.9