UI: fix and improve a few messages

- "can not" -> "cannot" in many places (ambiguous, also see
  Writing Style guide).
- "Bezier" -> "Bézier": proper spelling of the eponym.
- Tool keymaps: make "Uv" all caps.
- "FFMPEG" -> "FFmpeg" (official spelling)
- Use MULTIPLICATION SIGN U+00D7 instead of MULTIPLICATION X U+2715.
- "LClick" -> "LMB", "RClick" -> "RMB": this convention is used
  everywhere else.
- "Save rendered the image..." -> "Save the rendered image...": typo.
- "Preserve Current retiming": title case for property.
- Bend status message: punctuation.
- "... class used to define the panel" -> "header": copy-paste error.
- "... class used to define the menu" -> "asset": copy-paste error.
- "Lights user to display objects..." -> "Lights used...": typo.
- "-setaudio require one argument" -> "requires": typo.

Some issues reported by Joan Pujolar and Tamar Mebonia.

Pull Request: https://projects.blender.org/blender/blender/pulls/117856

intern/libmv/libmv/simple_pipeline/reconstruction_scale.cc

@@ -44,7 +44,7 @@ void EuclideanScaleToUnity(EuclideanReconstruction* reconstruction) {
   }
 
   if (max_distance == 0.0) {
-    LG << "Cameras position variance is too small, can not rescale";
+    LG << "Cameras position variance is too small, cannot rescale";
     return;
   }