Web console: Fix maxRowsPerSegment validation in hashed compaction spec

[vogievetsky]

Fixes an issue where a compaction spec, reflected back from Druid, with hashed partitioning will not validate in the compaction dialog. This is due to the fact that maxRowsPerSegment was renamed to targetRowsPerSegment but when Druid sends back the compaction config with targetRowsPerSegment becomes maxRowsPerSegment. As a result maxRowsPerSegment is not fully deprecated and must still be surfaced in the form for correct validation.

In addition to the above this PR also makes the following fixes:

• It is now possible to add a hidden field to the AutoForm. This means it can be validated correctly but will not surface in the form. This is needed for when targetRowsPerSegment will fully replace maxRowsPerSegment as we will still need to declare maxRowsPerSegment (as hidden) for the validation to work well with old configs that still use maxRowsPerSegment.
• The Submit button will now be disabled if there is an erroneous JSON state in JSON inputs. Preventing the user from being able to paste an invalid JSON and hit submit (submitting the default config).
• Date serialization was fixed in CSV/TSV download

This PR has:

• been self-reviewed.
• been tested in a test Druid cluster.

[suneet-s]

@vogievetsky it looks like the web-console-e2e-tests are failing. If you need to push another patch to fix this PR, can you merge master into your branch. #11283 was merged earlier today, so it should make travis run a lot faster for these web-console only changes 😄 🥳

[vogievetsky]

Happy days! Thank you for the tip @suneet-s and thank you for the work @clintropolis 🔥