Describe the problem

See #13231 (comment)

Describe the proposed solution

Attach location information to effects in development, so that it can be used when generating the error message. For simple cases where there's only a single effect involved we can do this sort of thing:

Uncaught Svelte error: effect_update_depth_exceeded
Maximum update depth exceeded in App.svelte:3:1. This can happen when a reactive block or effect repeatedly sets a new value. Svelte limits the number of nested updates to prevent infinite loops

If there are multiple effects running in a loop, the message could be more like this...

Uncaught Svelte error: effect_update_depth_exceeded
Maximum update depth exceeded. This can happen when a reactive block or effect repeatedly sets a new value. Svelte limits the number of nested updates to prevent infinite loops. Last ten effects:

App.svelte:3:1
App.svelte:10:1
App.svelte:3:1
App.svelte:10:1
App.svelte:3:1
App.svelte:10:1
App.svelte:3:1
App.svelte:10:1
App.svelte:3:1
App.svelte:10:1

...or we could try and be smarter about it so that we identify the actual loop (which aside from truly pathological cases should just be a case of going back until we see the most recent effect earlier in the stack?)

Importance

nice to have