Cannot add a `null` key to an input table, even for non-key columns

[mofojed]

Description

You cannot add a row that contains any null values to an input table, even though those are valid values. Even when explicitly setting a null value, it does not allow you to save it.

Steps to reproduce

1. Run the following snippet:

from deephaven import empty_table, input_table
_source1 = empty_table(5).update(["A=`` + i", "B=`` + i * 2", "C=i%2==1?null:i", "D=i * 2", "E=`` + i", "F=i%2==0?null:`` + i * 2",])
result1 = input_table(init_table=_source1, key_cols=["A", "B", "E", "F"])

2. Add values to a row for A, B, E, F (the key columns) and try and save

Expected results 2. The row should save, with null values for the non-key columns (C, D)

Actual results 2. An error is displayed saying "Key can't be empty"

Additional details and attachments Screenshot:

Also, we do seem to already have some special handling when we type in the value null into an input field (it adds the null value).

Versions

Engine Version: 0.35.2-SNAPSHOT Web UI Version: 0.85.2 Java Version: 11.0.23 Barrage Version: 0.6.0 Browser Name: Chrome 126 OS Name: Linux