Move LazyExpr's and MessageInfo's implementation to the combined TU

Some of the implementations were inlined instead.

src/catch2/internal/catch_message_info.cpp

@@ -1,26 +0,0 @@
-
-#include <catch2/internal/catch_message_info.hpp>
-
-namespace Catch {
-
-    MessageInfo::MessageInfo(   StringRef const& _macroName,
-                                SourceLineInfo const& _lineInfo,
-                                ResultWas::OfType _type )
-    :   macroName( _macroName ),
-        lineInfo( _lineInfo ),
-        type( _type ),
-        sequence( ++globalCount )
-    {}
-
-    bool MessageInfo::operator==( MessageInfo const& other ) const {
-        return sequence == other.sequence;
-    }
-
-    bool MessageInfo::operator<( MessageInfo const& other ) const {
-        return sequence < other.sequence;
-    }
-
-    // This may need protecting if threading support is added
-    unsigned int MessageInfo::globalCount = 0;
-
-} // end namespace Catch