Use monospaced font in query editor

[rumbin]

The code editor of the SQL queries uses a variable-spaced font instead of a monospaced one. This results in bad readability of the SQL code.

So the suggestion is to use a monospaced font. For reference, see https://github.com/grafana/grafana/issues/15414

[rumbin]

As an extension of this request, I'd like to share some thought on alternative ways to approach this issue:

Related issues with the current SQL query code editor:

• Tab key doues not indent, but jumps to next form field. This way, we cannot use Tab to indent/unindent highlighted blocks of code.
• The code window is sized too small. Only tiny queries fit in there without resizing the window of scrolling inside of it.
• Syntax highlighting is missing
• No multi-cursor selection

Maybe it would be an option to switch to Monaco editor, i.e., the web editor of VS Code? Some components/plugins of Grafana already seem to use it:

• https://github.com/grafana/monaco-logql
• https://github.com/grafana/azure-data-explorer-datasource/issues/219