Generic "getHash" helper

[webrgp]

Is your feature request related to a problem? Please describe.

The existing getCssHash won't return the hash if the css ins't included in a javascript entry.

Describe the solution you would like

Create a getHash that would behave just the same BUT it wouldn't check the "type" here, but just return the hash based on the filename returned from the manifest.

Additional context

This would allow us to have css entries (per v4.0.5) but still implement critical cookies.

[khalwat]

Given their changes to the manifest, probably this makes sense.

Have you removed that single line of code that tests the tag type? Does it work for your purposes with that removed?