TextEditor: make the format of completion item detail text adjustable

Instead of always assuming content in the form of rich text allow each
item individually to define it's text format for the detail text that is
shown as a tooltip of a completion item.

Fixes: QTCREATORBUG-22429
Change-Id: I9fa71373a743c26fa06d48acc5f0509584830ca0
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/clangcodemodel/clangassistproposalitem.cpp

@@ -495,6 +495,11 @@ bool ClangAssistProposalItem::isKeyword() const
     return m_codeCompletions[0].completionKind == CodeCompletion::KeywordCompletionKind;
 }
 
+Qt::TextFormat ClangAssistProposalItem::detailFormat() const
+{
+    return Qt::RichText;
+}
+
 bool ClangAssistProposalItem::isSnippet() const
 {
     return false;

src/plugins/clangcodemodel/clangassistproposalitem.h

@@ -48,6 +48,7 @@ public:
     QIcon icon() const final;
     QString detail() const final;
     bool isKeyword() const final;
+    Qt::TextFormat detailFormat() const final;
     bool isSnippet() const final;
     bool isValid() const final;
     quint64 hash() const final;

src/plugins/clangcodemodel/clangpreprocessorassistproposalitem.cpp

@@ -131,6 +131,11 @@ QString ClangPreprocessorAssistProposalItem::detail() const
     return QString();
 }
 
+Qt::TextFormat ClangPreprocessorAssistProposalItem::detailFormat() const
+{
+    return Qt::RichText;
+}
+
 bool ClangPreprocessorAssistProposalItem::isSnippet() const
 {
     return false;

src/plugins/clangcodemodel/clangpreprocessorassistproposalitem.h

@@ -51,6 +51,8 @@ public:
     void setDetail(const QString &detail);
     QString detail() const final;
 
+    Qt::TextFormat detailFormat() const final;
+
     bool isSnippet() const final;
     bool isValid() const final;