Add strict configuration file setting

[mildm8nnered]

Resolves #5220

Adds a strict configuration file setting, equivalent to the --strict command line option.

If --lenient is passed on the command line, this will take precendence over the configuration file.

[SwiftLintBot]

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📖	Linting Aerial with this PR took 1.18s vs 1.18s on main (0% slower)
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[SimplyDanny]

Thank you!