refactor: Switch plain errors in nodes-base to ApplicationError (no-changelog) (#7914)

Ensure all errors in `nodes-base` are `ApplicationError` or children of
it and contain no variables in the message, to continue normalizing all
the backend errors we report to Sentry. Also, skip reporting to Sentry
errors from user input and from external APIs. In future we should
refine `ApplicationError` to more specific errors.

Follow-up to: [#7877](https://github.com/n8n-io/n8n/pull/7877)

- [x] Test workflows:
https://github.com/n8n-io/n8n/actions/runs/7084627970
- [x] e2e: https://github.com/n8n-io/n8n/actions/runs/7084936861

---------

Co-authored-by: Michael Kret <michael.k@radency.com>

packages/nodes-base/nodes/MySql/v2/transport/index.ts

@@ -1,3 +1,4 @@
+import { ApplicationError } from 'n8n-workflow';
 import type { ICredentialDataDecryptedObject, IDataObject } from 'n8n-workflow';
 
 import mysql2 from 'mysql2/promise';
@@ -36,7 +37,9 @@ export async function createPool(
 	sshClient?: Client,
 ): Promise<Mysql2Pool> {
 	if (credentials === undefined) {
-		throw new Error('Credentials not selected, select or add new credentials');
+		throw new ApplicationError('Credentials not selected, select or add new credentials', {
+			level: 'warning',
+		});
 	}
 	const {
 		ssl,
@@ -94,7 +97,9 @@ export async function createPool(
 		return mysql2.createPool(connectionOptions);
 	} else {
 		if (!sshClient) {
-			throw new Error('SSH Tunnel is enabled but no SSH Client was provided');
+			throw new ApplicationError('SSH Tunnel is enabled but no SSH Client was provided', {
+				level: 'warning',
+			});
 		}
 
 		const tunnelConfig = await createSshConnectConfig(credentials);