fix: add support for migration of scrypt passwords

[J0]

What kind of change does this PR introduce?

Fix #1750. Scrypt passwords are widely used in certain systems like Firebase. We wish to allow support for use of Scrypt hashes so that developers can move over from Firebase (or similar) without the obligation to force a password reset for all users.

Firebase Scrypt differs from vanilla Scrypt - we highlight these changes in the comments

Hash format is:

$scrypt$n=<N>,r=<r>,p=<p>[,ss=<salt_separator>][,sk=<signer_key>]$<salt>$<hash>

$scrypt: Version Identifier
$n: N is the CPU/memory cost parameter.
$r: block size
$p: parallelization
$ss: salt seperator, optional, only if using firebase,  base64-encoded string used to separate the salt from other parameters.
$sk: signer key, a base64-encoded string used as an additional input to the hash function.
$<salt>: base64 encoded salt
$<hash>: base64 encoded output

Parameters used in the hash config
More details from CLI

[J0]

Suggested change

	return nil, fmt.Errorf("crypto: scrypt hash uses unsupported version $q only version 1 is supported", v)
	return nil, fmt.Errorf("crypto: scrypt hash uses unsupported version %q only version 1 is supported", v)