Validate numeric fields in submit file dialog

[karlaspuldaro]

Fixes #1516
The file submit dialog only validates fields marked as required.
This PR adds a validator for non-required numeric fields in the UI.

What changes were proposed in this pull request?

Added validation for numeric fields in submit file dialog. If the input is negative, disable the OK button

Also added descriptions to those resources fields to be consistent with pipeline node properties display.

How was this pull request tested?

Manual testing for invalid input from the keyboard, invalid input using the up/down arrows in the UI.
Checked pipeline run/submit dialog validation haven't changed.

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[akchinSTC]

Tested and looks good to me.

[lresende]

See comments above.

[marthacryan]

Haven't tested locally but the code LGTM. Thanks!