UI: Fix and improve a few messages

- "Show the result of running commands in the main interface...": add
  punctuation.
- "Re-Installed" -> "Reinstalled" seems more common.
- "increase_" and "decrease_subdivision" in the Grease Pencil
  modal...: use title case instead of snake case for label.
- "Use a automatic number..." -> "an", typo.
- "... points,{} splines": missing space.
- "End Frame is larger than Start Frame": wrong order in error message.
- "Approximate the object as sphere, which diameter is equal to
  thickness the defined...": grammar.
- "Show Seconds" -> "Use Timecode": this option is not necessarily about
  seconds. Suggested by Pablo Vasquez.
- Brightness and contrast node input descriptions: add missing spaces.
- "Gamma controls the relative intensity... full white.": remove
  trailing ".".

Pull Request: https://projects.blender.org/blender/blender/pulls/122972

scripts/addons_core/bl_pkg/cli/blender_ext.py

@@ -2439,7 +2439,7 @@ class subcmd_client:
             directories_to_clean.remove(filepath_local_pkg_temp)
 
         if is_reinstall:
-            message_status(msg_fn, "Re-Installed \"{:s}\"".format(manifest.id))
+            message_status(msg_fn, "Reinstalled \"{:s}\"".format(manifest.id))
         else:
             message_status(msg_fn, "Installed \"{:s}\"".format(manifest.id))