(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/gen-server/entity/Resource.ts

@@ -0,0 +1,46 @@
+import {BaseEntity, Column} from "typeorm";
+import {ApiError} from 'app/common/ApiError';
+import {CommonProperties} from "app/common/UserAPI";
+
+export class Resource extends BaseEntity {
+  @Column()
+  public name: string;
+
+  @Column({name: 'created_at', default: () => "CURRENT_TIMESTAMP"})
+  public createdAt: Date;
+
+  @Column({name: 'updated_at', default: () => "CURRENT_TIMESTAMP"})
+  public updatedAt: Date;
+
+  // a computed column which, when present, means the entity should be filtered out
+  // of results.
+  @Column({name: 'filtered_out', type: 'boolean', select: false, insert: false})
+  public filteredOut?: boolean;
+
+  public updateFromProperties(props: Partial<CommonProperties>) {
+    if (props.createdAt) { this.createdAt = _propertyToDate(props.createdAt); }
+    if (props.updatedAt) {
+      this.updatedAt = _propertyToDate(props.updatedAt);
+    } else {
+      this.updatedAt = new Date();
+    }
+    if (props.name) { this.name = props.name; }
+  }
+
+  protected checkProperties(props: any, keys: string[]): props is Partial<CommonProperties> {
+    for (const key of Object.keys(props)) {
+      if (!keys.includes(key)) {
+        throw new ApiError(`unrecognized property ${key}`, 400);
+      }
+    }
+    return true;
+  }
+}
+
+// Ensure iso-string-or-date value is converted to a date.
+function _propertyToDate(d: string|Date): Date {
+  if (typeof(d) === 'string') {
+    return new Date(d);
+  }
+  return d;
+}