Don't add noscript and change onload when already exists

When the input html contains a stylesheet which is already loaded async with the media strategy example:

<link rel="stylesheet" href="styles.40e2e5031a642e407437.css" media="print" onload="this.media='all'">
<noscript><link rel="stylesheet" href="styles.40e2e5031a642e407437.css"></noscript>

Critters will output an addition noscript tag and change the onload of the original link file.

- <link rel="stylesheet" href="styles.40e2e5031a642e407437.css" media="print" onload="this.media='all'">
+ <link rel="stylesheet" href="styles.40e2e5031a642e407437.css" media="print" onload="this.media='print'">
+ <noscript><link rel="stylesheet" href="styles.40e2e5031a642e407437.css" media="print"></noscript>
<noscript><link rel="stylesheet" href="styles.40e2e5031a642e407437.css"></noscript>

In this case while critters should extract the critical css it should not add an addition noscript tag nor change the onload to print.

[developit]

@alan-agius4 I think we could use this request as an interesting use-case for the plugin API @janicklas-ralph has been noodling on. It’s mainly aimed at additional HTML tree reduction, but it should be possible to have it also support marking nodes as “do not mutate”.

[alan-agius4]

@developit, we are using reduceInlineStyles:false.

The main reason for this is, so that between the transition from the SSR’d view to CSR view. Angular will remove/or re-use components <styles> generated on the server. However, when using reduceInlineStyles this is not possible because all styles are merged into a single style tag and causes metadata that is needed for styles to be be re-used to be lost, since this data is stored as attributed on style tags.

Overall, I am fine with closing this request. We did find a workaround to get around this.