Align `user.ip` between reporting SDKs

[vaind]

Depending on what SDK captures the event, there may be an IP address included for a given user (ID). We should align that to be the same across all types or events. AFAICT the IP address is there only for the cocoa SDK. The questions, for me, are:

1. should we include the IP address by default? -- depending on the setting.
2. should it depend on the "DefaultPII" setting? -- yes

[vaind]

It's done by the server for sentry-cocoa for historic reasons - can we turn it off on the server for Unity projects?

[vaind]

maybe workaround: try to send an empty string as the IP address

[bitsandfoxes]

We're populating the user in our ScopeIntegration here

sentry-unity/src/Sentry.Unity/Integrations/UnityScopeIntegration.cs

Lines 168 to 177 in e1ada0b

	private void PopulateUser(Scope scope)
	{
	if (_options.DefaultUserId is not null)
	{
	if (scope.User.Id is null)
	{
	scope.User.Id = _options.DefaultUserId;
	}
	}
	}

Any alignment of what else happens to the user seems to be required on the .NET SDK.

[bitsandfoxes]

The underlying SDKs should definitely align on when and what gets sent. And if this depends on the options provided to them (i.e. SendPII) then the Unity SDK must have appropriate default values.

[bitsandfoxes]

Resolved in the .NET SDK via getsentry/sentry-dotnet#3893
Coss-SDK tracking: getsentry/team-sdks#118