P8EMemorializeContract: Limit scope field changes.

[dwedul-figure]

…preserve its owners and value owners. Also only add to the data access list (instead of fully overwritting it).

Description

This PR makes the following changes to the processing done during P8EMemorializeContract:

1. If there's already a Scope with the given scope id, don't update the Owners or ValueOwnerAddress fields.
2. If there's already a scope with the given scope id, copy it's existing DataAccess values and add any new ones that might be missing (but don't remove any existing values).

Details:

Currently, during a P8EMemorializeContract call, the Scope.Owners, Scope.ValueOwnerAddress, and Scope.DataAccess values are populated using only info in the MsgP8EMemorializeContractRequest.

This has caused a problem in the following scenario:

1. MsgP8EMemorializeContractRequest is called with a contract just for an ORIGINATOR.
2. MsgP8EMemorializeContractRequest is called with a contract that has an ORIGINATOR and a SERVICING, that is to be added to the previously created scope.
3. MsgP8EMemorializeContractRequest is called again for the contract with just for an ORIGINATOR.

Problem: Now, both the ORIGINATOR and SERVICING parties are owners on the scope, so both need to sign for step number 3 (which would then actually remove the SERVICING owner).

After some discussion, we decided that we don't want MsgP8EMemorializeContractRequest to update the Scope.Owners, or Scope.ValueOwnerAddress fields. We also want the Scope.DataAccess values to only be additive. E.g., during step number 2 (above), the SERVICING party would be added to the DataAccess list, but during step 3, they'd still be there (they wouldn't be removed).

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Before we can merge this PR, please make sure that all the following items have been
checked off. If any of the checklist items are not applicable, please leave them but
write a little note why.

• Targeted PR against correct branch (see CONTRIBUTING.md)
• Linked to Github issue with discussion and accepted design OR link to spec that describes this work.
• Wrote unit and integration tests
• Updated relevant documentation (docs/) or specification (x/<module>/spec/)
• Added relevant godoc comments.
• Added a relevant changelog entry to the Unreleased section in CHANGELOG.md
• Re-reviewed Files changed in the Github PR explorer
• Review Codecov Report in the comment section below once CI passes

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (main@70b5f3b). Click here to learn what that means.
The diff coverage is 61.53%.

@@           Coverage Diff           @@
##             main     #336   +/-   ##
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  Coverage        ?   50.75%           
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  Files           ?      127           
  Lines           ?    11414           
  Branches        ?        0           
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  Hits            ?     5793           
  Misses          ?     5056           
  Partials        ?      565           

Impacted Files	Coverage Δ
x/metadata/keeper/msg_server.go	0.30% <0.00%> (ø)
x/metadata/keeper/keeper.go	80.51% <100.00%> (ø)

[iramiller]

Overall looks good... holding approve for a bit in light of automerge so the comment can be seen.

[channa-figure]

Nice work. LGTM

[iramiller]

Awesome.