Add SvelteKit client-side performance monitoring instrumentation

[Lms24]

Having basic error instrumentation, we can move on to performance monitoring.

We're going to add client-side performance monitoring instrumentation:

Tasks

Preview Give feedback

1. feat(sveltekit): Add wrapper for client load function #7447
   +0
   
2. feat(sveltekit): Automatically add BrowserTracing integration #7528
   +0
   
3. feat(sveltekit): Add SvelteKit routing instrumentation #7565
   +0
   
4. feat(sveltekit): Add performance monitoring for client load #7537
   +0
   
5. feat(sveltekit): Add partial instrumentation for client-side fetch #7626
   +0
   

For wrapping load and handle functions we should wait for the outcome of the error load wrapper in #7403. Thereafter, we can take my PoC from this discussion as a base: #5838 (reply in thread)

I also started work on a PoC routing instrumentation: https://gist.github.com/Lms24/b36a8f310410240863aa6e50dc19ab3d