Add Digest AKA to Algorithm Directive from RFC 3110 and RFC 4169

[tobiasfunke1]

Hi,

I added changes to match the definition for the algorithm directive from RFC 3310:

           algorithm           =  "algorithm" EQUAL ( aka-namespace
                                  / algorithm-value )
           aka-namespace       =  aka-version "-" algorithm-value
           aka-version         =  "AKAv" 1*DIGIT
           algorithm-value     =  ( "MD5" / "MD5-sess" / token )

~~Since the no Digest AKA is supported right now, I decided to return an error on the handle_digest_challenge method.~~ I added a second commit to add Digest AKA in the handle_digest_challenge method too.

Additional I decided to add some tests to check if the parsing works fine.

AKAv1: https://datatracker.ietf.org/doc/html/rfc3310#section-3.1 AKAv2: https://datatracker.ietf.org/doc/html/rfc4169#section-2

[tobiasfunke1]

I clean up the code and the commits, this PR is ready to review. @kbalt If you have time, can you please look at it?

For Digest AKA the password used to generate the digest response can contain non-ascii chars. So I change the type of the password to a vector of u8.

...
The resulting AKA RES parameter is treated as a "password" when
   calculating the response directive of [RFC 2617](https://datatracker.ietf.org/doc/html/rfc2617).

source: https://datatracker.ietf.org/doc/html/rfc3310#section-3.3

[tobiasfunke1]

Sorry, I accidentally closed this PR with a force push. Now it should be open again.

[kbalt]

Thanks for your effort, I will look into this when I have a bit of time to check everything out!

[tobiasfunke1]

Any updates on the review process?

[tobiasfunke1]

Thanks!