(core) move home server into core

Summary: This moves enough server material into core to run a home server.  The data engine is not yet incorporated (though in manual testing it works when ported).

Test Plan: existing tests pass

Reviewers: dsagal

Reviewed By: dsagal

Differential Revision: https://phab.getgrist.com/D2552

app/plugin/ImportSourceAPI-ti.ts

@@ -0,0 +1,44 @@
+/**
+ * This module was automatically generated by `ts-interface-builder`
+ */
+import * as t from "ts-interface-checker";
+// tslint:disable:object-literal-key-quotes
+
+export const ImportSourceAPI = t.iface([], {
+  "getImportSource": t.func(t.union("ImportSource", "undefined")),
+});
+
+export const ImportProcessorAPI = t.iface([], {
+  "processImport": t.func(t.array("GristTable"), t.param("source", "ImportSource")),
+});
+
+export const FileContent = t.iface([], {
+  "content": "any",
+  "name": "string",
+});
+
+export const FileListItem = t.iface([], {
+  "kind": t.lit("fileList"),
+  "files": t.array("FileContent"),
+});
+
+export const URL = t.iface([], {
+  "kind": t.lit("url"),
+  "url": "string",
+});
+
+export const ImportSource = t.iface([], {
+  "item": t.union("FileListItem", "URL"),
+  "options": t.opt(t.union("string", "Buffer")),
+  "description": t.opt("string"),
+});
+
+const exportedTypeSuite: t.ITypeSuite = {
+  ImportSourceAPI,
+  ImportProcessorAPI,
+  FileContent,
+  FileListItem,
+  URL,
+  ImportSource,
+};
+export default exportedTypeSuite;