Extract UI elements from storybook into new ui crate (#3008)

This PR extracts the various UI elements from the `storybook` crate into
a new `ui` library crate.

Release Notes:

- N/A

crates/storybook/Cargo.toml

@@ -17,6 +17,7 @@ serde.workspace = true
 settings = { path = "../settings" }
 simplelog = "0.9"
 theme = { path = "../theme" }
+ui = { path = "../ui" }
 util = { path = "../util" }
 
 [dev-dependencies]