Add pre-4.3 Editor theme color names for compatibility #616

Job	Run time
📊 Static checks / Code style, file formatting, and docs	4m 8s
🍏 iOS / Template (target=template_release)	11m 8s
🤖 Android / Template (target=template_release)	30m 10s
🍎 macOS / Editor (target=editor, tests=yes)	16m 15s
🐧 Linux / Editor w/ Mono (target=editor)	40m 36s
🍎 macOS / Template (target=template_release)	10m 51s
🐧 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)	40m 16s
🐧 Linux / Editor with clang sanitizers (target=editor, tests=yes, dev_build=yes, use_asan=yes, use_ubsan=yes, use_llvm=yes, linker=lld)	34m 40s
🏁 Windows / Editor (target=editor, tests=yes)	44m 49s
🐧 Linux / Editor with ThreadSanitizer (target=editor, tests=yes, dev_build=yes, use_tsan=yes, use_llvm=yes, linker=lld)	32m 42s
🏁 Windows / Template (target=template_release)	33m 4s
🐧 Linux / Template w/ Mono (target=template_release)	25m 13s
🐧 Linux / Minimal template (target=template_release, everything disabled)	17m 43s
🌐 Web / Template w/ threads (target=template_release, threads=yes)	22m 25s
🌐 Web / Template w/o threads (target=template_release, threads=no)	22m 35s
🪲 Godot CPP / Build and test Godot CPP	7m 26s
	6h 34m 1s

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