Improve Usability and Beautify Markdown Representation

[whateverforever]

This PR addresses a few open issues:

• Enhancement: Prettify Tables #19 all columns will be padded to the same width. This way, the raw markdown still looks nice and readable
• Feature request: down/up arrows should take you to the above/below row respectively #18 adds support for up/down arrows
• Translation Request: Use "Tabelle einfügen" instead of "markdown-table-editor" in DE #24 adds german translations
• Cut and paste does not work #15 strip cell before pasting

[JarnoB]

@haydenull Any chance in this pull request being merged? This would make a big difference for me in how well Logseq works for me.