Change referrer url size to 1500 #16835

fix https://github.com/matomo-org/matomo/issues/16810

Avoids running into row size exceeded in some cases.

Description:

Please include a description of this change and which issue it fixes. If no issue exists yet please include context and what problem it solves.

Review

• [ ] Functional review done
• [ ] Usability review done (is anything maybe unclear or think about anything that would cause people to reach out to support)
• [ ] Security review done see checklist
• [ ] Code review done
• [ ] Tests were added if useful/possible
• [ ] Reviewed for breaking changes
• [ ] Developer changelog updated if needed
• [ ] Documentation added if needed
• [ ] Existing documentation updated if needed

Tests pass so I'll merge this fyi @sgiehl @diosmosis

@tsteur should we trim the referer url to that length before storing it? otherwise it might fail when a database runs in strict mode but the referer was actually longer...

@sgiehl sure I'll add this in a bit