* chore: update editor file import to use procedures and substitute operator
* feat: refactor editor file-import UI to reuse filter from $:/config/Editor/EnableImportFilter
* feat: support for markdown in editor file import UI
* feat: improve markdown type detection and enable markdown image imports by default
* fix: uri encode tiddler titles for markdown
* escape characters instead of URI encoding
* fix: tweak regexp to simplify code and document escaping rules
e591dfd590