fix(core): pressing ENTER on database title now switches focus instead of creating new record (#13975)

Initial bug report: Issue
https://github.com/toeverything/AFFiNE/issues/13966

Description of bug: When a database header/title is in focus and the
user presses ENTER, a new record is created and shown to the user.

Expected outcome: When the user presses enter in the header title field,
the new title should be applied and then the title field should loose
focus.

Short summary of fix: When the ENTER key is pressed within the title,
the `onPressEnterKey()` function is called. As of now, this calls the
function `this.dataViewLogic.addRow?.('start');` which creates a new
record. In this fix, this has been changed to `this.input.blur()` which
instead essentially switches focus away from the title field and does
not create a new record, as expected.

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

* **Bug Fixes**
* Modified Enter key behavior in the database title field. Pressing
Enter now blurs the input instead of automatically inserting a new row.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

blocksuite/affine/blocks/database/src/components/title/index.ts

@@ -176,7 +176,7 @@ export class DatabaseTitle extends SignalWatcher(
   private readonly isFocus$ = signal(false);
 
   private onPressEnterKey() {
-    this.dataViewLogic.addRow?.('start');
+    this.input.blur();
   }
 
   get readonly$() {