Style tweaks for Conduit API console

Summary:

• Use pretty JSON formatter for human-readable Conduit output
• Fix some whitespace issues with format/layout.

Test Plan:

• Looked at conduit console.
• Looked at human-readable output of several calls.

Reviewed By: codeblock
Reviewers: codeblock, jungejason, tuomaspelkonen, aran
CC: aran, codeblock
Differential Revision: 740