Icon Library: Update Icon names to be app agnostic

[narin]

Description

Some of the names of our icons are very specific to the mobile app. One example is HealthSelected and HealthUnselected. We want to go through the icons and rename any app-specific icons to be more agnostic.

Note that some of these icons may be replaced or removed as part of the Icon Library epic and potential move to Google icons.

Acceptance Criteria

- [x] In the mobile-assets package, rename any app-specific icons to less specific names - [x] Delete `UploadPhoto` icon--it isn't actually used by the app anyway and is virtually identical to `ProfileSelected` - Done on #165 - [x] In the component-library package, update Icon component imports with the new icon names - [x] Update `svgs` folder to `icons` - [x] Move the DoD branch emblems to be their own assets folder as they are not really icons - [x] Move the VA logo to its' own assets folder as it is not really an icon - [x] Collapse the remaining folders that contain icons to be flat in the `icons` folder--an icon is an icon, the assets package should neither group by app-based functionality nor functional purpose already contained within the icon name

[jessicawoodin]

Note: This ticket may be addressed by #144 and/or #145.

[TimRoe]

Just to document: updated the ACs to also restructure the icons to be laid out more generically while we're reassessing naming.