(core) Adding schema validation for records endpoint

Summary:
Adding validation for api /records endpoint, that checks if the json payload is valid.
Modifying POST /records endpoint to allow creating blank or partial records.

Test Plan: Updated tests

Reviewers: alexmojaki

Reviewed By: alexmojaki

Differential Revision: https://phab.getgrist.com/D3061

app/plugin/CustomSectionAPI-ti.ts

@@ -1,3 +1,6 @@
+/**
+ * This module was automatically generated by `ts-interface-builder`
+ */
 import * as t from "ts-interface-checker";
 // tslint:disable:object-literal-key-quotes
 

app/plugin/FileParserAPI-ti.ts

@@ -1,3 +1,6 @@
+/**
+ * This module was automatically generated by `ts-interface-builder`
+ */
 import * as t from "ts-interface-checker";
 // tslint:disable:object-literal-key-quotes
 

app/plugin/GristData-ti.ts

@@ -0,0 +1,34 @@
+/**
+ * This module was automatically generated by `ts-interface-builder`
+ */
+import * as t from "ts-interface-checker";
+// tslint:disable:object-literal-key-quotes
+
+export const GristObjCode = t.enumtype({
+  "List": "L",
+  "Dict": "O",
+  "DateTime": "D",
+  "Date": "d",
+  "Skip": "S",
+  "Censored": "C",
+  "Reference": "R",
+  "ReferenceList": "r",
+  "Exception": "E",
+  "Pending": "P",
+  "Unmarshallable": "U",
+  "Versions": "V",
+});
+
+export const CellValue = t.union("number", "string", "boolean", "null", t.tuple("GristObjCode", t.rest(t.array("unknown"))));
+
+export const RowRecord = t.iface([], {
+  "id": "number",
+  [t.indexKey]: "CellValue",
+});
+
+const exportedTypeSuite: t.ITypeSuite = {
+  GristObjCode,
+  CellValue,
+  RowRecord,
+};
+export default exportedTypeSuite;

app/plugin/InternalImportSourceAPI-ti.ts

@@ -1,3 +1,6 @@
+/**
+ * This module was automatically generated by `ts-interface-builder`
+ */
 import * as t from "ts-interface-checker";
 // tslint:disable:object-literal-key-quotes
 

app/plugin/RenderOptions-ti.ts

@@ -1,3 +1,6 @@
+/**
+ * This module was automatically generated by `ts-interface-builder`
+ */
 import * as t from "ts-interface-checker";
 // tslint:disable:object-literal-key-quotes
 

app/plugin/StorageAPI-ti.ts

@@ -1,3 +1,6 @@
+/**
+ * This module was automatically generated by `ts-interface-builder`
+ */
 import * as t from "ts-interface-checker";
 // tslint:disable:object-literal-key-quotes