[LL FIR] designation refactoring

Collect `FirDesignation` by default with `FirFile` instead of just
a separate path and additional repeated logic around

^KT-65344

analysis/low-level-api-fir/testData/contextCollector/scripts/topLevel.copy.txt

@@ -53,8 +53,8 @@ Tower Data Context:
         Scope: FirLocalScope
 
 FILE: [ResolvedTo(IMPORTS)] topLevel.kts
-    context(<script>@R|kotlin/script/templates/standard/ScriptTemplateWithArgs|)
-    SCRIPT: [ResolvedTo(TYPES)] <script-topLevel.kts>
+    context(<script>@kotlin.script.templates.standard.ScriptTemplateWithArgs)
+    SCRIPT: [ResolvedTo(RAW_FIR)] <script-topLevel.kts>
         [ResolvedTo(RAW_FIR)] lval args: R|kotlin/Array<kotlin/String>|
 
         public? final? [ResolvedTo(RAW_FIR)] fun before_Fun(): R|kotlin/Unit| { LAZY_BLOCK }