[psi] move frontend independent string manipulators to psi.main module

this way IDE can drop dependency to old frontend,
when it's actually redundant

compiler/psi/src/org/jetbrains/kotlin/psi/psiUtil/KtStringTemplateExpressionManipulator.kt

@@ -0,0 +1,60 @@
+/*
+ * Copyright 2010-2023 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.psi.psiUtil
+
+import com.intellij.openapi.diagnostic.Logger
+import com.intellij.openapi.util.TextRange
+import com.intellij.openapi.util.text.StringUtil
+import com.intellij.psi.AbstractElementManipulator
+import org.jetbrains.kotlin.psi.KtExpression
+import org.jetbrains.kotlin.psi.KtPsiFactory
+import org.jetbrains.kotlin.psi.KtStringTemplateEntryWithExpression
+import org.jetbrains.kotlin.psi.KtStringTemplateExpression
+
+private val LOG = Logger.getInstance(KtStringTemplateExpressionManipulator::class.java)
+
+class KtStringTemplateExpressionManipulator : AbstractElementManipulator<KtStringTemplateExpression>() {
+    override fun handleContentChange(
+        element: KtStringTemplateExpression,
+        range: TextRange,
+        newContent: String
+    ): KtStringTemplateExpression? {
+        val node = element.node
+        val oldText = node.text
+
+        fun wrapAsInOld(content: String) = oldText.substring(0, range.startOffset) + content + oldText.substring(range.endOffset)
+
+        fun makeKtExpressionFromText(text: String): KtExpression {
+            val ktExpression = KtPsiFactory(element.project).createExpression(text)
+            if (ktExpression !is KtStringTemplateExpression) {
+                LOG.error("can't create a `KtStringTemplateExpression` from '$text'")
+            }
+            return ktExpression
+        }
+
+        val newContentPreprocessed: String =
+            if (element.isSingleQuoted()) {
+                val expressionFromText = makeKtExpressionFromText("\"\"\"$newContent\"\"\"")
+                if (expressionFromText is KtStringTemplateExpression) {
+                    expressionFromText.entries.joinToString("") { entry ->
+                        when (entry) {
+                            is KtStringTemplateEntryWithExpression -> entry.text
+                            else -> StringUtil.escapeStringCharacters(entry.text)
+                        }
+                    }
+                } else newContent
+            } else newContent
+
+        val newKtExpression = makeKtExpressionFromText(wrapAsInOld(newContentPreprocessed))
+        node.replaceAllChildrenToChildrenOf(newKtExpression.node)
+
+        return node.getPsi(KtStringTemplateExpression::class.java)
+    }
+
+    override fun getRangeInElement(element: KtStringTemplateExpression): TextRange {
+        return element.getContentRange()
+    }
+}

compiler/psi/src/org/jetbrains/kotlin/psi/psiUtil/StringTemplateExpressionManipulator.kt

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2010-2023 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.psi.psiUtil
+
+import com.intellij.psi.AbstractElementManipulator
+import org.jetbrains.kotlin.psi.KtStringTemplateExpression
+import com.intellij.openapi.util.TextRange
+import org.jetbrains.kotlin.psi.KtPsiFactory
+import com.intellij.openapi.util.text.StringUtil
+import kotlin.jvm.java
+import kotlin.text.substring
+
+class StringTemplateExpressionManipulator : AbstractElementManipulator<KtStringTemplateExpression>() {
+    override fun handleContentChange(
+        element: KtStringTemplateExpression,
+        range: TextRange,
+        newContent: String
+    ): KtStringTemplateExpression? {
+        val node = element.node
+        val content = if (node.firstChildNode.textLength == 1) StringUtil.escapeStringCharacters(newContent) else newContent
+        val oldText = node.text
+        val newText = oldText.substring(0, range.startOffset) + content + oldText.substring(range.endOffset)
+        val expression = KtPsiFactory(element.project).createExpression(newText)
+        node.replaceAllChildrenToChildrenOf(expression.node)
+        return node.getPsi(KtStringTemplateExpression::class.java)
+    }
+
+    override fun getRangeInElement(element: KtStringTemplateExpression): TextRange {
+        return element.getContentRange()
+    }
+}