Initial attempt to build out the test suite for DID resolution

[wip-abramson]

I tried to write a test for all MUST statements in sections 3. DID Parameters and sections 4. DID Resolution.

What this is missing:

• Fully fleshed out test for a conformant DID document (is there anything that can be reused from DID core here?)
• Some MUSTs I struggled to test (see Conformant representation test #5 and How to test statement about passing resolutionOptions to Read? #4)
• DID parameter tests are weird. I have mostly just tested the negative case. I.e. should fail on non-ascii strings. Positive tests are more challenging for many parameters because things like versionId and versionTime will depend on the DID method and the DID being resolved.

My code editor is also very unhappy with lots of angry red lines around going over the line length, among other things. Should I be trying to address this. It makes the code kinda hard to read when splitting on 80 chars.

Review and direction for moving this forward required. Thanks.