Report: the grid dialogs list floors down the left

Suite 2.246.12, Report 2.77.0.

What changed

Configure grid… lists the floors down the left of the dialog. Each floor is a button showing its name and the number of APs on it; the floor being edited is highlighted. Clicking a floor switches to it, with that floor's crop and combined sections as they were. This replaces the Floor plan dropdown above the plan.
Set up column grid… does the same. A tick beside a floor means its column grid is saved. The tick appears after Save this floor and goes after Turn off for this floor.
With more than 20 floors the dropdown is used instead. A report covering 21 or more floors shows the Floor plan dropdown in both dialogs, as before, rather than a long list. Up to 20 floors are listed; the list scrolls inside the left column.
Only the floors in the report are listed, the same set the dropdown offered: floors unticked under Floors to include are not shown.
The tick in the column-grid dropdown now clears when a floor is turned off. Previously it stayed until the dialog was reopened.
The step text in Configure grid… and the User Manual now describe the list and the 20-floor limit.

Tests render both dialogs from an invented three-floor project, take the click handler out of the rendered list, run it and check that the dialog moves to the chosen floor and the highlight follows. They check that a floor left out of the report is not listed, that the tick follows the saved column grids, and that 20 floors give the list while 21 give the dropdown. Each fails when the 20-floor limit is changed or the click no longer switches floors.
The dialog was checked visually in light and dark themes with twelve floors: the list sits in the left column, the current floor is highlighted in Report's colour, the list scrolls within the column, and the dropdown is hidden.
The full suite passes.