For UI:
- KDevelop supports both scripting and compiled languages, so e.g. debugging target can be non-binary
- external tools might be known as binary-only, but sometimes they are inside wrapper scripts and no place really requires a compiled binary
- consistent terms help users & also translators
For API/variable names:
- "executable" matches API of Qt
- consistent with UI language
Config storage keys not touched for now, might need more thinking.
Depends on D4592