feat(P.2.6): migrate bindings to v0.2.0 string-keys

6 input.bind() calls migrated from engine.input.KEY_* integers to
lowercase string-keys. Module is now engine.input.KEY_*-free (audit-
I3 resolved).

deps[]: lib-core.input version 0.1.0 → 0.2.0.

manifest.module

@@ -8,7 +8,7 @@
         {"id":"lib-core.maps","version":"0.1.0"},
         {"id":"lib-core.render","version":"0.1.0"},
         {"id":"lib-core.camera","version":"0.1.0"},
-        {"id":"lib-core.input","version":"0.1.0"},
+        {"id":"lib-core.input","version":"0.2.0"},
         {"id":"lib-core.player_control","version":"0.1.0"},
         {"id":"lib-core.interaction","version":"0.1.0"}
     ]