Set specific Drupal roles (including anonymous) for which person profiles should be created for (Fix js error "Unique user id has not been set in posthog.identify")

Alright, code wise this is done. Please review!

I will test it manually as well on Monday.

Alright, I had to adjust the Issue Summary Label.

Everything works as expected. E.g., when I only allow person profiles for "content editor" roles and create a new user with the "content editor" role the expected flow happens:
- I go to the site => PostHog logs, that an anonymous user is on the site.
- I login => PostHog creates a profile for the logged in user and connects it with the old anonymous account

I also created a user with the "Test" role. That user is not identified, even when logged in (as expected).

But for some reason, I still get the following error message:
~~~
logger.ts:50 [PostHog.js] Unique user id has not been set in posthog.identify
critical @ logger.ts:50
_validateIdentifyId @ posthog-core.ts:2310
identify @ posthog-core.ts:2380
(anonymous) @ index.ts:78
(anonymous) @ posthog-core.ts:1104
eachArray @ index.ts:16
(anonymous) @ posthog-core.ts:1096
_execute_array @ posthog-core.ts:1110
(anonymous) @ posthog-core.ts:4034
each @ index.ts:25
(anonymous) @ posthog-core.ts:4024
(anonymous) @ posthog-core.ts:4042
PendingScript
e.__SV.e.init @ cdn.js?tdsmkv:18
attach @ init.js?tdsmkv:42
(anonymous) @ drupal.js?v=11.3.5:166
Drupal.attachBehaviors @ drupal.js?v=11.3.5:162
(anonymous) @ drupal.init.js?v=11.3.5:32
listener @ drupal.init.js?v=11.3.5:20
~~~

Even though everything works as expected. I'll create a support request ticket to posthog, since in their documentation it is documented, that identify can be called without any arguments if "create_person_profile": "always" is set

Ok, this is super weird. Before creating the posthog ticket, I asked the AI if it knows a way to fix the js error being shown and interestingly enough it said the following:

Since person_profiles: 'always' is already set in the init_config (via posthog_js.module) when create_person_profile is true, PostHog automatically creates the person profile for the anonymous user without needing an identify() call.

This was very unexpected, since the documentation clearly states, that identify can be called without a distinct_id. But apparently, if "create_person_profiles" is set to "always" we always create person profiles, even without the "identify" call.

This is definitly true and also makes sense seeing the name of the config, but very unexpected, since the documentation says "identify()" can be called without a distinct id (which isn't true, since it throws an error), but instead we don't need to call "identify" entirely in that case (which is also not properly documented IMO):

This is straightforward to do when capturing backend events, as you associate events to a specific user using a distinct_id, which is a required argument.

However, in the frontend of a web or mobile app, a distinct_id is not a required argument — PostHog's SDKs will generate an anonymous distinct_id for you automatically and you can capture events anonymously, provided you use the appropriate configuration.

(https://posthog.com/docs/getting-started/identify-users)

Time to fix the tests now and we should be good to go.

Nice all green, let's get this merged!

Please do a final review! @anybody :)

Ok, I added both tests for posthog_js and commented out tests for posthog_js_conditional_profiles. Which should be refined in the future through a follow up issue, since we currently can't check, whether the person profiles are created or not.

Please review!