Better visualization for mixed and dictionaries

[gagik]

Is your feature request related to a problem? Please describe.
Since we're using flatted , the stringified output can be weird to read as a human; for example:
flatted.stringify([123]) == "[[123]]" or flatted.stringify([[123]]) == [["1"],[123]]`

Describe the solution you'd like
Use util.inspect to visualize these cases instead.

[sync-by-unito]

➤ PM Bot commented:

Jira ticket: RSTUDIO-539