[ui] Minor UI stabilization fixes for Qt 6

[cbentejac]

Description

This pull request fixes several minor UI issues following the merge of Qt 6:

• Correctly set the color of MaterialToolLabels (already existed before the merge of Qt 6);
• Explicitly set the color for the label of resectioned cameras in the Inspector3D;
• Fix the icon on the "Support AliceVision" button;
• Fix the icons in the grid view of projects on the Homepage;
• Use the correct style (Fusion) in the Inspector3D instead of Material;
• Add the missing imports to correctly display graphs related to the SfM statistics in the 2D Viewer;
• Fix the MouseArea located on the header of the expandable groups in the Inspector3D.