Simple ISO verification hashing done on the client

[RMcNeely]

Fixes #3179

Initial pass at providing a client-side way to verify the downloaded ISO file. Needs a lot more love but posting as a POC so someone with an x86 computer can validate.

Changes Summary

• Adds a page to verify the checksum of the download

This pull request is a draft that needs UI review

[4jNsY6fCVqZv]

@RMcNeely I am curious. Could you imagine showing a visual glimpse of the actual state of your POC?

[RMcNeely]

I can add something to show progress but I'm not sure that the way it is written I can easily add a progress bar given that the APIs are async. I would need to rewrite the file read operation to use chunks but to my knowledge, there's no way to do chunking on the hash creation so at best you would have a progress bar for only one part of the workflow.

I think it would be simpler to add a message that changes with the different steps of the verification process. Something like:

1. Reading ISO file
2. Creating Hash
3. Other? Stringifiying the hash and comparing it to an expected value would both be very quick operations. I'm not sure thats worth displaying something for.