Fix transform calculations for drag-moving CanvasItems in editor #83

Job	Run time
📊 Static checks / Code style, file formatting, and docs	3m 19s
🍏 iOS / Template (target=template_release)	2m 58s
🍎 macOS / Editor (target=editor, tests=yes)	47m 42s
🍎 macOS / Template (target=template_release)	3m 51s
🤖 Android / Template (target=template_release)	4m 1s
🐧 Linux / Editor w/ Mono (target=editor)	3m 57s
🐧 Linux / Editor with doubles and GCC sanitizers (target=editor, tests=yes, dev_build=yes, scu_build=yes, precision=double, use_asan=yes, use_ubsan=yes, linker=gold)	27m 11s
🌐 Web / Template (target=template_release)	1m 29s
🐧 Linux / Editor with clang sanitizers (target=editor, tests=yes, dev_build=yes, use_asan=yes, use_ubsan=yes, use_llvm=yes, linker=lld)	8m 16s
🏁 Windows / Editor (target=editor, tests=yes)	12m 24s
🐧 Linux / Editor with ThreadSanitizer (target=editor, tests=yes, dev_build=yes, use_tsan=yes, use_llvm=yes, linker=lld)	9m 30s
🏁 Windows / Template (target=template_release)	9m 38s
🐧 Linux / Template w/ Mono (target=template_release)	2m 30s
🐧 Linux / Minimal template (target=template_release, everything disabled)	1m 3s
🪲 Godot CPP / Build and test Godot CPP	9m 36s
	2h 27m 25s

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