UI
Main issue is that the UI doesn not respect the Unified Weight/Strength
setting (but instead alwasy shows the brushes weight/strength)
Was working before, but somewhat missed in rBfb74dcc5d69d.
See discussion in T74025 on why the Gradient Tool in its current state
is not very user friendly in general, what I think we should do though
is at least have the values in the UI respect Unified Weight / Unified
Strength since this is what the tool will use internally...
ref T74025
Maniphest Tasks: T74025
Differential Revision: https://developer.blender.org/D6900