libcamera: color_space: Add fromString() function

Add a ColorSpace:fromString() function to parse a string into a color
space. The string can either contain the name of a well-known color
space, or four color space components separate by a '/' character.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Umang Jain <umang.jain@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>

include/libcamera/color_space.h

@@ -59,6 +59,8 @@ public:
 
 	std::string toString() const;
 	static std::string toString(const std::optional<ColorSpace> &colorSpace);
+
+	static std::optional<ColorSpace> fromString(const std::string &str);
 };
 
 bool operator==(const ColorSpace &lhs, const ColorSpace &rhs);