refactor: Use named exports instead of default exports (#2238)

* use named exports instead of default exports

* fix tests

Co-authored-by: Philipp Kühn <philippkuehn@MacBook-Pro-von-Philipp.local>

tests/cypress/integration/core/extendExtensions.spec.ts

@@ -1,7 +1,7 @@
 /// <reference types="cypress" />
 
 import { Extension } from '@tiptap/core/src/Extension'
-import getExtensionField from '@tiptap/core/src/helpers/getExtensionField'
+import { getExtensionField } from '@tiptap/core/src/helpers/getExtensionField'
 
 describe('extend extensions', () => {
   it('should define a config', () => {

tests/cypress/integration/core/fromString.spec.ts

@@ -1,6 +1,6 @@
 /// <reference types="cypress" />
 
-import fromString from '@tiptap/core/src/utilities/fromString'
+import { fromString } from '@tiptap/core/src/utilities/fromString'
 
 describe('fromString', () => {
   it('should return a string', () => {

tests/cypress/integration/core/isClass.spec.ts

@@ -1,6 +1,6 @@
 /// <reference types="cypress" />
 
-import isClass from '@tiptap/core/src/utilities/isClass'
+import { isClass } from '@tiptap/core/src/utilities/isClass'
 
 describe('isClass', () => {
   it('returns true for classes', () => {

tests/cypress/integration/core/mergeAttributes.spec.ts

@@ -1,6 +1,6 @@
 /// <reference types="cypress" />
 
-import mergeAttributes from '@tiptap/core/src/utilities/mergeAttributes'
+import { mergeAttributes } from '@tiptap/core/src/utilities/mergeAttributes'
 
 describe('mergeAttributes', () => {
   it('should merge two objects', () => {

tests/cypress/integration/core/mergeDeep.spec.ts

@@ -1,6 +1,6 @@
 /// <reference types="cypress" />
 
-import mergeDeep from '@tiptap/core/src/utilities/mergeDeep'
+import { mergeDeep } from '@tiptap/core/src/utilities/mergeDeep'
 
 describe('mergeDeep', () => {
   it('should merge', () => {

tests/cypress/integration/extensions/codeBlockLowlight.spec.ts

@@ -1,8 +1,6 @@
 /// <reference types="cypress" />
 
-import {
-  CodeBlockLowlight,
-} from '@tiptap/extension-code-block-lowlight'
+import { CodeBlockLowlight } from '@tiptap/extension-code-block-lowlight'
 import { Text } from '@tiptap/extension-text'
 import { Paragraph } from '@tiptap/extension-paragraph'
 import { Document } from '@tiptap/extension-document'