Fix AdvancedPaste auto-copy failing on Electron/Chromium apps (e.g. Teams)

WM_COPY message is delivered successfully to Electron apps but silently
ignored, so the clipboard never changes. The old code treated WM_COPY
delivery as success and never fell back to SendInput Ctrl+C.

Now each attempt tries both strategies: WM_COPY first (fast path for
standard Win32 controls), then Ctrl+C via SendInput if the clipboard
sequence didn't change (needed for Electron/Chromium/browser apps).

Also extracted send_ctrl_c_input() and poll_clipboard_sequence() helpers
for clarity.