feat: Implement add a “align” parameter for ui.inline

[Nicolapps]

This PR adds a new align parameter to ui.inline that allows users to specify the vertical alignment of the items.

The API is updated as follows:

 interface Inline {
   /** The components laid out inline. */
   items: Component[]
   /** Specifies how to lay out the individual components. Defaults to 'start'. */
   justify?: 'start' | 'end' | 'center' | 'between' | 'around'
+  /** Specifies how the individual components are aligned on the vertical axis. Defaults to 'center'. */
+  align?: 'start' | 'end' | 'center' | 'baseline' | 'stretch'
   /** Whether to display the components inset from the parent form, with a contrasting background. */
   inset?: B
 }

The PR also adds a new example showing how values for the justify and align parameters of ui.inline work:

ui_inline_demo.mov

I also renamed the alignment parameter of the internal function XComponents to justify (more details here: 08d6813).

Closes 1535.

[monal20]

Looks good to me. Note that I looked over the files in ui/src and examples.