lib:enable support for utf-16 encoding in blob

[ankittripathi1]

fixes: #58718

add support for utf-16 encoding in blog decoder.

[Ethan-Arrowood]

Couldn't this be any valid charset option? Maybe better to generalize this and add support for a custom charset for the decoding

[KhafraDev]

this isn't spec-compliant. https://w3c.github.io/FileAPI/#dom-blob-text

[ankittripathi1]

Sorry i overlooked that the text() method supposed to always decode as UTF-8 according to specs.
Would it make more sense to add a separate method like textwithencoding(charset)?

[jasnell]

We generally do not add non-standard methods to standard APIs so adding a new textwithencoding method wouldn't work. Adding encoding support directly to blob likely is a non-starter. You can, fairly trivially combine use of Blob with TextEncoder/TextDecoder to get the necessary encoding support.

[jasnell]

this is a change that should be proposed upstream in the spec first.

[ankittripathi1]

Then should I close this PR?

[jasnell]

Yeah, closing I think is best.

[jimmywarting]

Hmm, annoying that different env behave differently...