KT-6608 Code completion does not work after $ in string literals

KT-5070 Add braces when complete function in string templates

 #KT-6608 Fixed
 #KT-5070 Fixed

idea/testData/completion/basic/common/StringTemplate1.kt

@@ -0,0 +1,6 @@
+fun foo(param: String) {
+    val s = "$<caret>"
+}
+
+// EXIST: foo
+// EXIST: param

idea/testData/completion/basic/common/StringTemplate2.kt

@@ -0,0 +1,6 @@
+fun foo(param: String) {
+    val s = "${<caret>}"
+}
+
+// EXIST: foo
+// EXIST: param

idea/testData/completion/handlers/basic/stringTemplate/1.kt

@@ -0,0 +1,5 @@
+fun foo(): String {
+    val s = "$<caret>"
+}
+
+// ELEMENT: foo

idea/testData/completion/handlers/basic/stringTemplate/1.kt.after

@@ -0,0 +1,5 @@
+fun foo(): String {
+    val s = "${foo()<caret>}"
+}
+
+// ELEMENT: foo

idea/testData/completion/handlers/basic/stringTemplate/2.kt

@@ -0,0 +1,5 @@
+fun foo(p: String): String {
+    val s = "$<caret>"
+}
+
+// ELEMENT: foo

idea/testData/completion/handlers/basic/stringTemplate/2.kt.after

@@ -0,0 +1,5 @@
+fun foo(p: String): String {
+    val s = "${foo(<caret>)}"
+}
+
+// ELEMENT: foo

idea/testData/completion/handlers/basic/stringTemplate/3.kt

@@ -0,0 +1,5 @@
+fun foo(): String {
+    val s = "${<caret>}"
+}
+
+// ELEMENT: foo

idea/testData/completion/handlers/basic/stringTemplate/3.kt.after

@@ -0,0 +1,5 @@
+fun foo(): String {
+    val s = "${foo()<caret>}"
+}
+
+// ELEMENT: foo

idea/testData/completion/handlers/basic/stringTemplate/4.kt

@@ -0,0 +1,5 @@
+fun foo(param: Any): String {
+    val s = "${<caret>}"
+}
+
+// ELEMENT: param

idea/testData/completion/handlers/basic/stringTemplate/4.kt.after

@@ -0,0 +1,5 @@
+fun foo(param: Any): String {
+    val s = "${param<caret>}"
+}
+
+// ELEMENT: param

idea/testData/completion/handlers/basic/stringTemplate/NotEmptyPrefix.kt

@@ -0,0 +1,7 @@
+fun bar() {}
+
+fun test(){
+    "$b<caret>"
+}
+
+// ELEMENT: bar

idea/testData/completion/handlers/basic/stringTemplate/NotEmptyPrefix.kt.after

@@ -0,0 +1,7 @@
+fun bar() {}
+
+fun test(){
+    "${bar()<caret>}"
+}
+
+// ELEMENT: bar

idea/testData/completion/handlers/basic/stringTemplate/Replace.kt

@@ -0,0 +1,6 @@
+fun foo(): String {
+    val s = "$<caret>xxx"
+}
+
+// ELEMENT: foo
+// CHAR: \t

idea/testData/completion/handlers/basic/stringTemplate/Replace.kt.after

@@ -0,0 +1,6 @@
+fun foo(): String {
+    val s = "${foo()<caret>}"
+}
+
+// ELEMENT: foo
+// CHAR: \t