Create "Select workspace type" dialog and add to workspace menu

how a user selects a different workspace type than the one they're in (this ticket)
how workspace-specific features are added to the menu (#1839)

Add `Select workspace type` option to workspace menu.

Menu has three groups:

context-specific actions
workspace tools
settings/share/export

If there is more than one workspace type available in the implementation, add Select workspace type option to group 2.

Open selection dialog.

User selects Select workspace type. Close the menu and open a dialog centered in the window. The available worktypes are displayed in horizontal blocks.

Each block includes:

icon
radio button and label
descriptive text

Icons and their accompanying radio buttons/labels are clickable to select a workspace type. Selection is not applied until the user clicks SWITCH.

Cancel closes the dialog without changing the workspace.

Mobile layout

reduce the size of the icon
float the text to the right of the icon/radio button pair
align the options vertically

Initial text

Move and size windows freely in an unlimited workspace. Windows can overlap.
Not responsive; retains layout and size when shared.

Move and size windows within a scrollable grid.
Responsive; adjusts window size and flow to the viewing device.`

Move and size windows in relation to each other, within the visible frame.
Responsive. Ideal for embedded presentations.

Icons Can provide placeholder SVG icons, but I'm not able attach them here...

Switch workspace type (magic)

There will need to be additional design work on this and a separate ticket. Initial intent is that windows will flow into the new layout in more or less their location order top left to bottom right; either normalize windows to a consistent size or retain some degree of their relative sizes as allowed by the new layout.

ProjectMirador / mirador