[Analysis API] Generify 'KtCodeFragmentModule' to support ordinary files

This commit introduces dangling file modules, which may be either
code fragments or ordinary Kotlin files. As before, code fragments are
analyzed against some context element, however ordinary files only
have a context module.

Code fragments can also have a dangling file module as a contextual one,
including other code fragment. This is done to support potential usages
in completion, intentions and refactorings.

analysis/analysis-api-standalone/analysis-api-standalone-base/src/org/jetbrains/kotlin/analysis/api/standalone/base/project/structure/KtStaticModuleProvider.kt

@@ -8,7 +8,7 @@ package org.jetbrains.kotlin.analysis.api.standalone.base.project.structure
 import com.intellij.psi.PsiElement
 import com.intellij.psi.PsiFileSystemItem
 import org.jetbrains.kotlin.analysis.project.structure.*
-import org.jetbrains.kotlin.analysis.project.structure.impl.KtCodeFragmentModuleImpl
+import org.jetbrains.kotlin.analysis.project.structure.impl.KtDanglingFileModuleImpl
 import org.jetbrains.kotlin.config.LanguageVersionSettings
 import org.jetbrains.kotlin.psi.KtCodeFragment
 import org.jetbrains.kotlin.psi.psiUtil.contains
@@ -31,7 +31,7 @@ class KtStaticModuleProvider(
                     .withAttachment("codeFragment.kt", containingPsiFile.text)
 
             val contextModule = getModule(contextElement, contextualModule)
-            return KtCodeFragmentModuleImpl(containingPsiFile, contextModule)
+            return KtDanglingFileModuleImpl(containingPsiFile, contextModule)
         }
 
         val containingVirtualFile = containingPsiFile.virtualFile