(core) Reference and ReferenceList formatters

Summary:
Previously, ref/reflist columns were formatted entirely based on their visible column, since they received values from the visible or display columns rather than the actual row IDs. This creates `ReferenceFormatter` and `ReferenceListFormatter` which still delegate most of the formatting work to a visible column formatter but fix a few issues:

- ReferenceList columns now actually use the options (e.g. date format) of the visible column to format their elements. Previously they were formatted generically because the visible column formatter wasn't expecting a list.
- Invalid references aren't formatted with an `#Invalid Ref` prefix.
- When the ref column displays the Row ID, it doesn't have a visible or display column. Previously this led to the references being formatted as just numbers in most cases, with special code in the widget to display them like `Table1[2]`. Now they are consistently formatted in that style throughout.

Test Plan: Updated existing tests.

Reviewers: jarek

Reviewed By: jarek

Subscribers: dsagal

Differential Revision: https://phab.getgrist.com/D3212

app/common/ValueParser.ts

@@ -11,6 +11,7 @@ import NumberParse from 'app/common/NumberParse';
 import {parseDateStrict, parseDateTime} from 'app/common/parseDate';
 import {MetaRowRecord, TableData} from 'app/common/TableData';
 import {DateFormatOptions, DateTimeFormatOptions, formatDecoded, FormatOptions} from 'app/common/ValueFormatter';
+import {encodeObject} from 'app/plugin/objtypes';
 import flatMap = require('lodash/flatMap');
 import mapValues = require('lodash/mapValues');
 
@@ -177,7 +178,7 @@ export class ReferenceListParser extends ReferenceParser {
       // csvDecodeRow should never raise an exception
       values = csvDecodeRow(raw);
     }
-    values = values.map(v => typeof v === "string" ? this._visibleColParser(v) : v);
+    values = values.map(v => typeof v === "string" ? this._visibleColParser(v) : encodeObject(v));
 
     if (!values.length || !raw) {
       return null;  // null is the default value for a reference list column