Move handler into CoreService and adopt

This also fine tunes some of the data events to not clear selection
and scroll to the bottom of the viewport anymore.

Part of #1507
Fixes #2112

src/common/TestUtils.test.ts

@@ -3,7 +3,7 @@
  * @license MIT
  */
 
-import { IBufferService, IOptionsService, ITerminalOptions, IPartialTerminalOptions } from 'common/services/Services';
+import { IBufferService, ICoreService, IOptionsService, ITerminalOptions, IPartialTerminalOptions } from 'common/services/Services';
 import { IEvent, EventEmitter } from 'common/EventEmitter';
 import { clone } from 'common/Clone';
 import { DEFAULT_OPTIONS } from 'common/services/OptionsService';
@@ -27,6 +27,12 @@ export class MockBufferService implements IBufferService {
   reset(): void {}
 }
 
+export class MockCoreService implements ICoreService {
+  onData: IEvent<string> = new EventEmitter<string>().event;
+  onUserInput: IEvent<void> = new EventEmitter<void>().event;
+  triggerDataEvent(data: string, wasUserInput?: boolean): void {}
+}
+
 export class MockOptionsService implements IOptionsService {
   options: ITerminalOptions = clone(DEFAULT_OPTIONS);
   onOptionChange: IEvent<string> = new EventEmitter<string>().event;