refactor(app): Use new DID creation patterns; updated docs

[DRK3]

• Updated the demo apps to use the new DID creation patterns.
• Updated the JS bindings to use the new DID creation patterns.
• Updated docs.
• Fixed an issue where the P256 key type string constant wasn't accessible from the mobile bindings.
• Other minor refactoring.

[codecov-commenter]

Codecov Report

Patch and project coverage have no change.

Comparison is base (78b4c79) 89.73% compared to head (17ce39b) 89.73%. Report is 3 commits behind head on main.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #617 +/- ## ======================================= Coverage 89.73% 89.73% ======================================= Files 102 102 Lines 4014 4014 ======================================= Hits 3602 3602 Misses 274 274 Partials 138 138 ``` | [Files Changed](https://app.codecov.io/gh/trustbloc/wallet-sdk/pull/617?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=trustbloc) | Coverage Δ | | |---|---|---| | [cmd/wallet-sdk-gomobile/localkms/localkms.go](https://app.codecov.io/gh/trustbloc/wallet-sdk/pull/617?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=trustbloc#diff-Y21kL3dhbGxldC1zZGstZ29tb2JpbGUvbG9jYWxrbXMvbG9jYWxrbXMuZ28=) | `69.44% <ø> (ø)` | | | [pkg/did/creator/jwk/jwk.go](https://app.codecov.io/gh/trustbloc/wallet-sdk/pull/617?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=trustbloc#diff-cGtnL2RpZC9jcmVhdG9yL2p3ay9qd2suZ28=) | `100.00% <ø> (ø)` | | | [pkg/did/creator/key/key.go](https://app.codecov.io/gh/trustbloc/wallet-sdk/pull/617?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=trustbloc#diff-cGtnL2RpZC9jcmVhdG9yL2tleS9rZXkuZ28=) | `77.27% <ø> (ø)` | |

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.

[sonarcloud[bot]]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
1 Code Smell

No Coverage information
4.0% Duplication