[FIR] Remove line breaks after context receivers in diagnostic messages

#KT-62944 Fixed

compiler/testData/diagnostics/tests/extensions/contextReceivers/contextReceiverAmbiguity.diag.txt

@@ -0,0 +1,5 @@
+/contextReceiverAmbiguity.kt:13:9: error: overload resolution ambiguity:
+context(String) public fun foo(x: Comparable<*>): Unit defined in root package in file contextReceiverAmbiguity.kt
+context(String) public fun foo(x: Number): Unit defined in root package in file contextReceiverAmbiguity.kt
+        foo(1)
+        ^

compiler/testData/diagnostics/tests/extensions/contextReceivers/contextReceiverAmbiguity.fir.diag.txt

@@ -0,0 +1 @@
+/contextReceiverAmbiguity.kt:(203,206): error: Overload resolution ambiguity between candidates: [context(String) fun foo(x: Comparable<*>): Unit, context(String) fun foo(x: Number): Unit]

compiler/testData/diagnostics/tests/extensions/contextReceivers/contextReceiverAmbiguity.kt

@@ -0,0 +1,15 @@
+// FIR_IDENTICAL
+// !LANGUAGE: +ContextReceivers
+// RENDER_DIAGNOSTICS_FULL_TEXT
+
+context(String)
+fun foo(x: Comparable<*>) {}
+
+context(String)
+fun foo(x: Number) {}
+
+fun test() {
+    with("") {
+        <!OVERLOAD_RESOLUTION_AMBIGUITY!>foo<!>(1)
+    }
+}