List is based on Vim's documentation, although not all digraphs are documented. Additional digraphs are added based on the output of `:digraphs`. These additional digraphs include some digraphs that produce the same character, so the code is updated to handle duplicates, with the same ordering/priority as Vim.
Extra digraphs include the Euro symbol (`=e` and `Eu`), quadruple prime (`4'`) and bullet (`oo`), amongst others.
Also removes a number of non-standard digraphs. The symbols generated don't match the descriptions. The code appears to be private use, so are not reliable. Once custom digraphs are implemented, they can be easily added back in `~/.ideavimrc`
Vim only use the `~` prefix if the encoding is "latin1". We can just treat it as though the encoding is Unicode, and match the other places we format printable characters. Note that for Vim, if `'display'` contains "uhex", then all unprintable characters are shown in hex, including control characters (`^C`, etc.). IdeaVim does not support the `'display'` option.
`OperatorArguments.mode` is the mode *before* the command was completed, rather than the current mode, which is non-obvious. E.g. for a command in Insert mode, it will still be Insert, and for a (simple) command in Normal, it will still be Normal. The only difference is that a command such as `dw` would be in Operator-pending before the command is completed. That logic is not required for this method, so it's safe to use the current mode.
This allows us to start to deprecate `OperatorArguments.mode`.
`OperatorArguments.mode` is the mode *before* the command is completed, so might be Visual, Operator-pending, Insert, etc. It's not immediately obvious this is the case, so we're going to deprecate `OperatorArguments.mode` to avoid confusion with `editor.mode`.
It's not required for this method because it's only called for Visual-block mode.
Register specific handlers for Operator-pending mode instead of relying on a runtime flag for behaviour. Also refactors and renames some arrow motion handlers.
