fix(pii): Mark sentry_user field as PII

[loewenheim]

This marks User::sentry_user as PII so it gets scrubbed correctly.

Fixes #3917.

#skip-changelog

[Dav1dde]

Is extracting after PII scrubbing feasible?

This works now for IP addresses but not custom rules where the Sentry user specifically targets the ip field.

[jjbayer]

mini nit: I would put this field declaration right after name, i.e. group it with the fields it is constructed from.

[loewenheim]

Is extracting after PII scrubbing feasible?

This works now for IP addresses but not custom rules where the Sentry user specifically targets the ip field.

I tried switching around PII stripping and normalization (where sentry_user is set) and it broke a test by changing the reported browser name. I don't think I can predict the consequences of making that change.

[jjbayer]

I tried switching around PII stripping and normalization (where sentry_user is set) and it broke a test by changing the reported browser name. I don't think I can predict the consequences of making that change.

Yes I'm afraid we cannot move all of event normalization after PII scrubbing. But we could introduce a new "post-pii normalization" step that for now only contains the creation of the sentry_user field. Tricky part is making sure the trimming processor still runs after that.

[Dav1dde]

Fixes the issue at hand for now, thinking about re-ordering processing is probably a not so easy/big task, think we should move forward with this. @jjbayer wdyt?

[jjbayer]

Fixes the issue at hand for now, thinking about re-ordering processing is probably a not so easy/big task, think we should move forward with.

Yep