refactor: replace language with IDEA api

Author: phodal

core/src/main/kotlin/cc/unitmesh/devti/sketch/ui/code/EditorUtil.kt

@@ -16,6 +16,7 @@ import com.intellij.openapi.editor.ex.EditorMarkupModel
 import com.intellij.openapi.editor.ex.FocusChangeListener
 import com.intellij.openapi.editor.ex.MarkupModelEx
 import com.intellij.openapi.editor.highlighter.EditorHighlighterFactory
+import com.intellij.openapi.fileTypes.PlainTextLanguage
 import com.intellij.openapi.project.Project
 import com.intellij.openapi.vfs.VirtualFile
 import com.intellij.testFramework.LightVirtualFile
@@ -32,13 +33,14 @@ object EditorUtil {
         disposable: Disposable,
     ): EditorEx {
         var editorText = text
-        val language = ideaLanguage ?: CodeFence.findLanguage("Plain text")
-        val ext = if (language.displayName == "Plain text") {
+        val language = ideaLanguage ?: PlainTextLanguage.INSTANCE
+        val ext = if (language.displayName == PlainTextLanguage.INSTANCE.displayName) {
             CodeFence.lookupFileExt(language.displayName)
         } else {
             language.associatedFileType?.defaultExtension ?: "Unknown"
         }
-        /// check text easyline starts with Lineno and :, for example: 1:
+
+        /// check text easy line starts with Lineno and : for example, 1:
         var isShowLineNo = true
         editorText.lines().forEach {
             if (!it.matches(LINE_NO_REGEX)) {