add an endpoint for doing SQL selects (#641)

* add an endpoint for doing SQL selects

This adds an endpoint for doing SQL selects directly on a Grist document. Other kinds of statements are not supported. There is a default timeout of a second on queries.

This follows loosely an API design by Alex Hall.

Co-authored-by: jarek <jaroslaw.sadzinski@gmail.com>

app/server/lib/SqliteNode.ts

@@ -1,6 +1,6 @@
 import * as sqlite3 from '@gristlabs/sqlite3';
 import { fromCallback } from 'app/server/lib/serverUtils';
-import { MinDB, PreparedStatement, ResultRow, SqliteVariant } from 'app/server/lib/SqliteCommon';
+import { MinDB, MinDBOptions, PreparedStatement, ResultRow, SqliteVariant } from 'app/server/lib/SqliteCommon';
 import { OpenMode, RunResult } from 'app/server/lib/SQLiteDB';
 
 export class NodeSqliteVariant implements SqliteVariant {
@@ -84,6 +84,17 @@ export class NodeSqlite3DatabaseAdapter implements MinDB {
     this._db.close();
   }
 
+  public async interrupt(): Promise<void> {
+    this._db.interrupt();
+  }
+
+  public getOptions(): MinDBOptions {
+    return {
+      canInterrupt: true,
+      bindableMethodsProcessOneStatement: true,
+    };
+  }
+
   public async allMarshal(sql: string, ...params: any[]): Promise<Buffer> {
     // allMarshal isn't in the typings, because it is our addition to our fork of sqlite3 JS lib.
     return fromCallback(cb => (this._db as any).allMarshal(sql, ...params, cb));