Cosmos: Create shadow property for id if key cannot be used

[AndriySvyryd]

Fixes #35325

[Copilot]

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

Comments suppressed due to low confidence (2)

src/EFCore.Cosmos/Metadata/Conventions/CosmosJsonIdConvention.cs:121

• Check the changes related to computedIdPropertyBuilder for unintended side effects.

if (clrType == typeof(string) && keyProperty.Builder.CanSetJsonProperty(IdPropertyJsonName))

src/EFCore.Cosmos/Metadata/Conventions/CosmosPartitionKeyInPrimaryKeyConvention.cs:79

• The method 'PrimaryKey' does not exist on 'IConventionEntityTypeBuilder'. It should be 'HasKey'.

entityTypeBuilder.PrimaryKey(primaryKeyProperties);