[libcalamares] Mark CommandLine as public, expand API a little

src/libcalamares/utils/CommandList.h

@@ -29,7 +29,7 @@ namespace Calamares
  * Each command can have an associated timeout in seconds. The timeout
  * defaults to 10 seconds. Provide some convenience naming and construction.
  */
-class CommandLine
+class DLLEXPORT CommandLine
 {
 public:
     static inline constexpr std::chrono::seconds TimeoutNotSet() { return std::chrono::seconds( -1 ); }
@@ -92,6 +92,9 @@ public:
         }
     }
 
+    /** @brief Unconditionally set verbosity (can also reset it to nullopt) */
+    void setVerbose( std::optional< bool > v ) { m_verbose = v; }
+
 private:
     QString m_command;
     QStringList m_environment;