HPCC-31447 ECL Watch v9 fix dropdown widths

correct the default behaviour for FluentUI v8 dropdowns to truncate
option text to the width of the input, instead fitting to the content

Signed-off-by: Jeremy Clements <79224539+jeclrsg@users.noreply.github.com>

esp/src/src-react/components/forms/Fields.tsx

@@ -136,8 +136,8 @@ const AsyncDropdown: React.FunctionComponent<AsyncDropdownProps> = ({
     }, [onChange, selectedItem, selectedIdx, selectedKey]);
 
     return options === undefined ?
-        <DropdownBase label={label} options={[]} placeholder={nlsHPCC.loadingMessage} disabled={true} /> :
-        <DropdownBase label={label} options={selOptions} selectedKey={selectedItem?.key} onChange={(_, item: IDropdownOption) => setSelectedItem(item)} placeholder={placeholder} disabled={disabled} required={required} errorMessage={errorMessage} className={className} />;
+        <DropdownBase label={label} dropdownWidth="auto" options={[]} placeholder={nlsHPCC.loadingMessage} disabled={true} /> :
+        <DropdownBase label={label} dropdownWidth="auto" options={selOptions} selectedKey={selectedItem?.key} onChange={(_, item: IDropdownOption) => setSelectedItem(item)} placeholder={placeholder} disabled={disabled} required={required} errorMessage={errorMessage} className={className} />;
 };
 
 interface DropdownMultiProps {