Set wxICON_INFORMATION as amule welcome icon - #295

…ect#295)

The preferences dialog's page list (General, Connection, Directories,
etc.) fed 16x16 bitmaps into a fixed-size wxImageList, so on
DPI-aware builds the icons render at 16 physical pixels — tiny and
blurry on hi-DPI screens, same problem as the main toolbar (amule-project#294).

Hand the icons to the list control as wxBitmapBundles instead
(wxListCtrl::SetSmallImages, wx >= 3.2), each built from the 16px art
plus a wxIMAGE_QUALITY_HIGH 2x upscale with the mask converted to an
alpha channel first. The macOS-only right/bottom padding is applied
per resolution so the padded canvas keeps its proportions at 2x.

Co-authored-by: Carlos Barrero <[email protected]>
Co-authored-by: Claude Fable 5 <[email protected]>

…#307)

Follow-up to amule-project#295: the old `#ifdef __WXOSX__` right/bottom pads (14/9)
compensated for `AssignImageList`'s NSTableView render path — zero
native icon/text gap plus vertical-centre-of-the-full-bitmap, which
made a bare 16x16 icon sit flush against the label and drift toward
the row baseline. `SetSmallImages` uses a different wxOSX path that
already inserts native icon/text spacing, so the pads now render as
visible extra whitespace between icon and label. Drop them (and the
now-dead `img.Size()` pass) so wxOSX matches Windows/Linux layout.

Verified locally: rebuilt on macOS 15 ARM64 (wxOSX Cocoa 3.3.2), page
icons now sit at the natural offset the wx-native path picks. No
change on wxGTK or wxMSW paths (both pads were already 0 there).