[Code health] Reorganize component directories and modules

[gino-m]

Based on https://medium.com/@dolanmiu/angular-folder-structure-follow-the-dom-8af5453d0808 and discussion with nwotto@, suggesting the following:

• One component = one directory = one module.
• Subcomponent's directories should be nested under their parent component's directory
• Components used in >1 place should live in components/
• Components defining page roots should live under pages/

The resulting folder hierarchy under web/ would look something like this:

src
  app
    components
      shared-component-1
      shared-component-2
    converters
    models
    pages
      page-1
        subcomponent-1
          subcomponent-1a
          subcomponent-1b
          ...
        subcomponent-2  
          ....
    service

Names of components only used in one place can be shortened when name is clear from context.

We'll keep ground- element prefix as per recommendation in Angular style guide:
https://angular.io/guide/styleguide#style-02-07

@DaoyuT @amysorto @nwkotto FYI

[gino-m]

I already started this, need to verify all components were reorganized.