Progress bar widget

[Songtronix]

This will add a very primitive progressbar:

What additionally can be done:

• make it customizable by accepting colors.
• allow the use of a border
• optional label in the middle showing the percentage
• make progressbar render on the web

[hecrj]

Looks great! Thank you. 🎉

I left some feedback, let me know what you think!

[Songtronix]

Hmm I can't get the tour to compile to wasm. Either my setup is messed up or some dependency isn't wasm compatible anymore.

error[E0599]: no method named `as_sock` found for type `&std::net::TcpStream` in the current scope
   --> /home/songtronix/.cargo/registry/src/github.com-1ecc6299db9ec823/net2-0.2.33/src/ext.rs:855:25
    |
855 |         do_connect(self.as_sock(), addr)
    |                         ^^^^^^^ method not found in `&std::net::TcpStream`
    |
    = help: items from traits can only be used if the trait is implemented and in scope
    = note: the following trait defines an item `as_sock`, perhaps you need to implement it:
            candidate #1: `ext::AsSock`

[hecrj]

This is probably a dev dependency, maybe surf? Rust will try to compile all the dev dependencies even if they are not used by the example you are trying to build.

Although it would be great to use a cross-platform HTTP client, maybe we could make the dev dependency conditional based on the target for the time being. This way, the examples that do not use it could still be compiled.

[Songtronix]

Okay disabling almost all dev dependencies helped. I'll try to get the progressbar working on the web.

[Songtronix]

Well implementing the progressbar for the web is harder than I thought, instead I've fixed the text_input for the web to support being a password field if required. (This fixes the tour example to be compiling again).

[hecrj]

I have moved the DEFAULT_HEIGHT constant to the Renderer trait and fixed some minor documentation issues.

I will be happy to merge this in its current state. We can improve it and add iced_web support in further PRs.

Let me know what you think.

[Songtronix]

Good idea to move the default height over to the render. I'm fine with merging it 👌