feat: integrate dioxus-logger inline

[jkelleyrtp]

Inlines dioxus-logger so we can add better CLI support to it during the 0.6 release cycle.

Also cuts down on the verbosity of setting up logging in all of our examples.

This PR adds a new method to the logger:

pub fn initialize_default() {
     if tracing::dispatcher::has_been_set() {
         return;
     }

     if cfg!(debug_assertions) {
         _ = init(Level::DEBUG);
     } else {
         _ = init(Level::INFO);
     }
 }

The new method is basically "set up the logger the way dioxus would set up the logger".

This way, if you're doing custom logging setups, you can simply put ours first:

use dioxus::prelude::*;
use tracing::info;

fn main() {
    dioxus::logger::initialize_default();

    info!("Doing some work before launching...");

    dioxus::launch(App);
}

#[component]
fn App() -> Element {
    info!("App rendered");
    rsx! {
        p { "hi" }
    }
}

We should eventually add a function that builds our custom logging layer in case people want to extend our layer with their layer.