moved callback to leptos root and improved design #870

Job	Run time
get-leptos-changed / Detect Source Change	11s
CI (integrations/actix) / Run ci (nightly)	16m 53s
CI (integrations/utils) / Run ci (nightly)	17m 34s
CI (integrations/axum) / Run ci (nightly)	17m 30s
CI (integrations/viz) / Run ci (nightly)	16m 30s
CI (leptos) / Run ci (nightly)	1h 46m 25s
CI (leptos_dom) / Run ci (nightly)	25m 59s
CI (leptos_macro) / Run ci (nightly)	30m 49s
CI (leptos_config) / Run ci (nightly)	21m 35s
CI (leptos_reactive) / Run ci (nightly)	37m 32s
CI (leptos_hot_reload) / Run ci (nightly)	18m 1s
CI (leptos_server) / Run ci (nightly)	32m 22s
CI (meta) / Run ci (nightly)	16m 49s
CI (router) / Run ci (nightly)	18m 23s
CI (server_fn) / Run ci (nightly)	16m 11s
CI (server_fn_macro) / Run ci (nightly)	20m 24s
CI (server_fn/server_fn_macro_default) / Run ci (nightly)	15m 14s
	7h 8m 22s

Provide feedback