Header text can be automatically translated according to the po dictionary

[chenpaner]

1. Modified the get_header_text function in all operators so that the hints in it can be automatically translated according to the po dictionary
2. add translations，I've only added Chinese and Japanese translations, users can add new translations themselves!
3. In line 156 of the base_tool.py file, the "/" shortcut shows "eraser size", but I tested it should be "local view", I'm not sure if it's correct, if I'm wrong please fix it back!

[semagnum]

Hi, thank you so much for handling this! I'm excited to support multiple languages for my add-ons, so it's much appreciated.

Here are the changes I need from you before I can review this:

• Remove all the files contained in __pycache__ folders - they're built per local machine, so having them in the repo is redundant (and likely overwritten once downloaded anyway). I disabled pycache generation locally but I'll add them to the gitignore for future reference.
• The files are shown as if the entire files were changed when you likely only changed a few lines - I'm guessing this is due to how Windows vs non-Windows machines do new lines. If you could undo your changes so the new lines correctly match what's already in the repo, I'd appreciate it.