keys in did documents should list controller instead of owner

[ugoamanoh]

What's Here

This resolves the issue #29

• Updated the owner key in DIDDocument to controller as stated in the DID spec
• Updated existing tests

Testing

Rund the entire test suite using the command ./gradlew test cC --no-parallel

[codecov]

Codecov Report

Merging #33 into develop will increase coverage by 0.69%.
The diff coverage is 100%.

@@              Coverage Diff              @@
##             develop      #33      +/-   ##
=============================================
+ Coverage      72.69%   73.38%   +0.69%     
- Complexity       181      182       +1     
=============================================
  Files             24       24              
  Lines            868      868              
  Branches         145      145              
=============================================
+ Hits             631      637       +6     
+ Misses           159      152       -7     
- Partials          78       79       +1

Impacted Files	Coverage Δ	Complexity Δ
.../main/java/me/uport/sdk/ethrdid/EthrDIDResolver.kt	81.76% <100%> (ø)	21 <0> (ø)	⬇️
...n/java/me/uport/sdk/jwt/test/EthrDIDTestHelpers.kt	94.73% <100%> (ø)	1 <0> (ø)	⬇️
...ava/me/uport/sdk/uportdid/UportIdentityDocument.kt	72.09% <100%> (ø)	4 <0> (ø)	⬇️
...main/java/me/uport/sdk/universaldid/DIDDocument.kt	64.1% <100%> (ø)	0 <0> (ø)	⬇️
jwt/src/main/java/me/uport/sdk/jwt/JWTTools.kt	85.02% <0%> (+3.59%)	59% <0%> (+1%)	⬆️

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[mirceanis]

This is a good start towards adhering to the latest W3C definitions but there are also existing DIDs out there that would fail with this proposed version.

Real-world existing web dids will crash with this change:

@Test
fun `can resolve real web did`() {
    val doc = WebDidResolver().resolve("did:web:uport.me")
}

Since the existing testing data was also changed, the current tests don't reflect real world behavior.
We should have a test to support parsing of older-style DIDs. This test should hardcode an old format DID doc and verify that it is resolved properly.

This problem will manifest for web-did and uport-did documents since they are stored somewhere and not generated at runtime like ethr-did

[mirceanis]

Adapting to legacy DID doc formats is tricky without support from the serialization lib.

This PR should make it easier to completely cover the above cases:
Kotlin/kotlinx.serialization#597