Offer keyboard shortcut for editor reformatting

[mavam]

A user asked whether it's possible to provide a canonical formatting option in the editor to represent a pipeline in a readable manner.

In splunk you can press Ctrl+Shift+F and the query gets formatted in the input field, for me this is good enough for every day work.

We yet have to discuss what reformatting actually does. For example, let's say this is "canoncial form" (example from the docs):

/* 1. Start pipeline to data at a Tenzir node */
export
/* 2. Filter out a subset of events (predicate gets pushed down) */
| where #schema == "zeek.weird" && note == "SSL::Invalid_Server_Cert"
/* 3. Aggregate them by destination IP */
| summarize count(num) by id.resp_h
/* 4. Sort by frequency */
| sort
/* 5. Take the top-20 items */
| head 20
/* 6. Write the output as JSON to standard output */
| write json to stdout

The idea is that a user can start writing export | where ... | summarize ... and then hitting the keyboard shortcut would bring the pipeline into the above form, with newlines and spacing properly linted.