(core) Allows range filter for Date, DateTime columns

Summary:
This diff is first of a series of 3 commits to enable range filering
for Date and DateTime columns. Diff only enable setting date's min/max
throw typing dates, Date picker and relative ranges are left for
follow-up commits.

 - Exposes columns value formatter to the range input
 - Fixes column filter func to work with dates

Test Plan:
Adds Date to projects range filter test
Adds Date/DateTime to nbrowser ColumnFilterMenu tests

Reviewers: alexmojaki

Reviewed By: alexmojaki

Subscribers: alexmojaki

Differential Revision: https://phab.getgrist.com/D3455

app/common/ColumnFilterFunc.ts

@@ -1,18 +1,18 @@
 import {CellValue} from "app/common/DocActions";
 import {FilterState, isRangeFilter, makeFilterState} from "app/common/FilterState";
 import {decodeObject} from "app/plugin/objtypes";
-import {isList, isListType, isNumberType} from "./gristTypes";
+import {isDateLikeType, isList, isListType, isNumberType} from "./gristTypes";
 
 export type ColumnFilterFunc = (value: CellValue) => boolean;
 
 // Returns a filter function for a particular column: the function takes a cell value and returns
 // whether it's accepted according to the given FilterState.
 export function makeFilterFunc(state: FilterState,
-                               columnType?: string): ColumnFilterFunc {
+                               columnType: string = ''): ColumnFilterFunc {
 
   if (isRangeFilter(state)) {
     const {min, max} = state;
-    if (isNumberType(columnType)) {
+    if (isNumberType(columnType) || isDateLikeType(columnType)) {
       return (val) => {
         if (typeof val !== 'number') { return false; }
         return (

app/common/gristTypes.ts

@@ -329,6 +329,10 @@ export function isNumberType(type: string|undefined) {
   return ['Numeric', 'Int'].includes(type || '');
 }
 
+export function isDateLikeType(type: string) {
+  return type === 'Date' || type.startsWith('DateTime');
+}
+
 export function isFullReferencingType(type: string) {
   return type.startsWith('Ref:') || isRefListType(type);
 }