refactor: rename record fields

[shumkov]

Issue being fixed or feature implemented

According to the original idea, DPNS can resolve information from any services or network (not just located in dash network), including IPFS, various identity services, etc. Also we have naming convention to use Id postfix in case if we pointing to identifier.

What was done?

• Renamed records.identity to records.dashIdentityId

How Has This Been Tested?

Updated existing tests

Breaking Changes

None

Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have added or updated relevant unit/integration/functional/e2e tests
• I have added "!" to the title and described breaking changes in the corresponding section if my code contains any
• I have made corresponding changes to the documentation if needed

For repository code-owners and collaborators only

• I have assigned this pull request to a milestone

[QuantumExplorer]

The record you are looking at is for an identity, not an identityId. While the underlying item is represented by an identityId it's not common practice to name the underlying representation but instead name the business logic item. This is the case in DNS and ENS.

As for DashIdentity vs Identity, common practice in the industry has been to not prefix with your own blockchain. This makes things cheaper for our users as the records are slightly smaller.