Debugger: Do not use expression code fragments for evaluator (KT-32736, KT-32741)

It seems like it doesn't make much sense to create expression code fragments.
People type statements or several expressions separated with a semicolon to a single-line expression line.
That is exactly what block code fragment was designed for.

idea/jvm-debugger/jvm-debugger-test/testData/evaluation/singleBreakpoint/functionDeclaration.kt

@@ -0,0 +1,9 @@
+package functionDeclaration
+
+fun main() {
+    //Breakpoint!
+    val a = 5
+}
+
+// EXPRESSION: fun foo() {}
+// RESULT: VOID_VALUE

idea/jvm-debugger/jvm-debugger-test/testData/evaluation/singleBreakpoint/functionDeclaration.out

@@ -0,0 +1,8 @@
+LineBreakpoint created at functionDeclaration.kt:5
+Run Java
+Connected to the target VM
+functionDeclaration.kt:5
+Compile bytecode for fun foo() {}
+Disconnected from the target VM
+
+Process finished with exit code 0

idea/jvm-debugger/jvm-debugger-test/testData/evaluation/singleBreakpoint/statements.kt

@@ -0,0 +1,9 @@
+package statements
+
+fun main() {
+    //Breakpoint!
+    val a = 5
+}
+
+// EXPRESSION: val b = 1
+// RESULT: VOID_VALUE

idea/jvm-debugger/jvm-debugger-test/testData/evaluation/singleBreakpoint/statements.out

@@ -0,0 +1,8 @@
+LineBreakpoint created at statements.kt:5
+Run Java
+Connected to the target VM
+statements.kt:5
+Compile bytecode for val b = 1
+Disconnected from the target VM
+
+Process finished with exit code 0