Fix ValueGenerated On Add Or Update, , make ValueGeneratedOnUpdate() and ValueGeneratedOnAddOrUpdate() working

[eation]

Fixes #6999 and #19765
docs #3165

When useing ValueGeneratedOnUpdate(), set PropertyBuilder.Metadata.SetAfterSaveBehavior(PropertySaveBehavior.Save) for update.

When useing ValueGeneratedOnAddOrUpdate(), set PropertyBuilder.Metadata.SetBeforeSaveBehavior(PropertySaveBehavior.Save) for add and PropertyBuilder.Metadata.SetAfterSaveBehavior(PropertySaveBehavior.Save) for update.

[eation]

@ajcvickers @AndriySvyryd
Can Cosmos modify explicitly or default PK value with a temporary value on state changed?

efcore/test/EFCore.Cosmos.FunctionalTests/Internal/IdentifierShadowValuePresenceTest.cs

Lines 35 to 57 in 50f8b84

	public async Task Entities_can_be_tracked_with_normal_use_of_DbContext_methods_and_have_correct_resultant_state_and_id_shadow_value()
	{
	await using var testDatabase = CosmosTestStore.Create("IdentifierShadowValuePresenceTest");
	using var context = new IdentifierShadowValuePresenceTestContext(testDatabase);
	var item = new Item { Id = 1337 };
	var entry = context.Attach(item);
	Assert.Equal($"Item|{item.Id}", entry.Property("__id").CurrentValue);
	Assert.Equal(EntityState.Unchanged, entry.State);
	entry.State = EntityState.Detached;
	entry = context.Update(item = new Item { Id = 71 });
	Assert.Equal($"Item|{item.Id}", entry.Property("__id").CurrentValue);
	Assert.Equal(EntityState.Modified, entry.State);
	entry.State = EntityState.Detached;
	entry = context.Remove(item = new Item { Id = 33 });
	Assert.Equal($"Item|{item.Id}", entry.Property("__id").CurrentValue);
	Assert.Equal(EntityState.Deleted, entry.State);
	}

Related issues and pull requests

[AndriySvyryd]

#4073 (and #19135) would need to be fixed first

[Saibamen]

Wrong formatting

[Saibamen]

Wrong formatting

[Saibamen]

Wrong formatting?

[eation]

@Saibamen Not sure,but this src file auto-format by vs after last marge

[ajcvickers]

As @AndriySvyryd mentioned above, making this kind of change is dangerous without more generally updating the handling of modified key properties, as tracked by #4073 and #19135, and possibly other issues. This kind of change would also need significant new testing to make sure it does not result in bad state that cannot be handled by other parts of the stack. For these reasons, this is not a change we plan to merge.