Revert "make non-fillable fields visible but disabled in UI"

This reverts commit f2aad9caac.

app/src/data/fields/field-test-suite.ts

@@ -99,7 +99,6 @@ export function fieldTestSuite(
       const _config = {
          ..._requiredConfig,
          required: false,
-         fillable: true,
       };
 
       function fieldJson(field: Field) {
@@ -117,7 +116,10 @@ export function fieldTestSuite(
 
       expect(fieldJson(fillable)).toEqual({
          type: noConfigField.type,
-         config: _config,
+         config: {
+            ..._config,
+            fillable: true,
+         },
       });
 
       expect(fieldJson(required)).toEqual({
@@ -148,6 +150,7 @@ export function fieldTestSuite(
          type: requiredAndDefault.type,
          config: {
             ..._config,
+            fillable: true,
             required: true,
             default_value: config.defaultValue,
          },