* Fix hashed ID server lookups with no Olm
It used the hash function from Olm (presumably to work cross-platform)
but subtle crypto is available on node nowadays so we can just use
that.
Refactor existing code that did this out to a common function, add
tests.
* Test the code when crypto is available
* Test case of no crypto available
* Move digest file to src to get it out of the way of the olm / e2e stuff
* Fix import
* Fix error string & doc
* subtle crypto, not webcrypto
* Extract the base64 part
* Fix test
* Move test file too
* Add more doc
* Fix imports
David Baker
89a9a7fa38