Improvements - multi-select and some performance optimizations

[AsYlum-]

• Added multi-select for compare plugins.
• Animation edit form: add anim6.mul support and a gallery. Changed how animation files are loaded .
• Optimized file loading times and memory usage across many controls.
• Replace TreeView with faster controls in TileData, Sounds, RadarCol, Multis, Light, and Dress tabs for quicker loading and scrolling.
• "Select in..." cross-tab navigation now activates the target main tab and reliably selects the row (fixes TileData "Save Changes" silently failing). Same fix applied to Items, LandTiles, RadarCol, Textures, Gumps, AnimData.
• Dark mode color fixes: replace hardcoded Color.Blue/Color.Red/Color.Black with theme-aware alternatives (CornflowerBlue, OrangeRed, SystemColors.ControlText) across SkillGroup, RadarCol, Sounds, Light, Textures, Gumps, Map, Hues, LandTiles, Items, and the Hue edit form.
• Hue edit form preview now uses the configured preview background color instead of hardcoded white.
• Improved radarcol color generation and control layout.
• Compare map status strip menu moved to context menu under right mouse button for easier access. Added mouse wheel zoom.
• Multi select possible for items, land tiles and textures.
• Added filter to animation tab
• Added gallery preview to animation editor
• Improved load times for animation tab
• Added second animation overlay to animation editor
• Added zoom option to animation editor
• Fixed application failure to exit when profile selection form was closed without any selection.
• Fixed crash when exporting altitude map image with View markers enabled.