Web console: Fix required field treatment

[vogievetsky]

This PR fixes a bug in the data loader flow when connecting Kinesis.

The issue is that the Endpoint field looks like it is filled in with the default value but it also is required so it requires input.
The issue is fixed as a one line change in ingestion-spec.tsx per the docs the endpoint field is not required.

In addition to fixing this issue:

• AutoForm has been upgraded so that defaultValue is ignored when required is evaluated to true
• Tests have been greatly expanded
• I scanned the code for more instances of this issue and found one in the TIMESTAMP_SPEC_FIELDS
• Added the ability to Alt+Shift+Click a tile in the ingestion screen to go to its connection step even if the extension is not loaded.

This PR has:

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

[suneet-s]

@vogievetsky Do we know when this bug was introduced? I'm wondering if this is bad enough to justify backporting this to 0.21.1 release.

[vogievetsky]

@suneet-s the fact that the endpoint field was incorrectly marked as required was there from the start of the data loader but until #10533 it just resulted in an incorrect border color that people would not even notice. #10533 started using the model definitions as validation also and that is when the original bug went from being (from a user perspective) almost unnoticeable to flow breaking. I think it is worth back-porting this.

[suneet-s]

@clintropolis fyi I added the milestone 0.21.1 to this bug so we can backport it before making the patch release