ci: Introduce no-plain-errors lint rule for BE packages (no-changelog) (#7961)

## Summary
Require `ApplicationError` or its child classes instead of plain `Error`
in BE packages. This ensures the error will be normalized when reported
to Sentry, if applicable.

Follow-up to:
https://github.com/n8n-io/n8n/pulls?q=is%3Apr+is%3Aclosed+applicationerror

...

#### How to test the change:
1. ...


## Issues fixed
Include links to Github issue or Community forum post or **Linear
ticket**:
> Important in order to close automatically and provide context to
reviewers

...


## Review / Merge checklist
- [ ] PR title and summary are descriptive. **Remember, the title
automatically goes into the changelog. Use `(no-changelog)` otherwise.**
([conventions](https://github.com/n8n-io/n8n/blob/master/.github/pull_request_title_conventions.md))
- [ ] [Docs updated](https://github.com/n8n-io/n8n-docs) or follow-up
ticket created.
- [ ] Tests included.
> A bug is not considered fixed, unless a test is added to prevent it
from happening again. A feature is not complete without tests.
  >
> *(internal)* You can use Slack commands to trigger [e2e
tests](https://www.notion.so/n8n/How-to-use-Test-Instances-d65f49dfc51f441ea44367fb6f67eb0a?pvs=4#a39f9e5ba64a48b58a71d81c837e8227)
or [deploy test
instance](https://www.notion.so/n8n/How-to-use-Test-Instances-d65f49dfc51f441ea44367fb6f67eb0a?pvs=4#f6a177d32bde4b57ae2da0b8e454bfce)
or [deploy early access version on
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packages/nodes-base/nodes/CompareDatasets/GenericFunctions.ts

@@ -259,11 +259,8 @@ export function findMatches(
 
 	if (disableDotNotation && skipFields.some((field) => field.includes('.'))) {
 		const fieldToSkip = skipFields.find((field) => field.includes('.'));
-		throw new Error(
-			`Dot notation is disabled, but field to skip comparing '${
-				fieldToSkip as string
-			}' contains dot`,
-		);
+		const msg = `Dot notation is disabled, but field to skip comparing '${fieldToSkip}' contains dot`;
+		throw new ApplicationError(msg, { level: 'warning' });
 	}
 
 	const filteredData = {
@@ -403,16 +400,18 @@ export function findMatches(
 
 export function checkMatchFieldsInput(data: IDataObject[]) {
 	if (data.length === 1 && data[0].field1 === '' && data[0].field2 === '') {
-		throw new Error(
+		throw new ApplicationError(
 			'You need to define at least one pair of fields in "Fields to Match" to match on',
+			{ level: 'warning' },
 		);
 	}
 	for (const [index, pair] of data.entries()) {
 		if (pair.field1 === '' || pair.field2 === '') {
-			throw new Error(
+			throw new ApplicationError(
 				`You need to define both fields in "Fields to Match" for pair ${index + 1},
 				 field 1 = '${pair.field1}'
 				 field 2 = '${pair.field2}'`,
+				{ level: 'warning' },
 			);
 		}
 	}
@@ -447,7 +446,10 @@ export function checkInputAndThrowError(
 			return get(entry.json, field, undefined) !== undefined;
 		});
 		if (!isPresent) {
-			throw new Error(`Field '${field}' is not present in any of items in '${inputLabel}'`);
+			throw new ApplicationError(
+				`Field '${field}' is not present in any of items in '${inputLabel}'`,
+				{ level: 'warning' },
+			);
 		}
 	}
 	return input;