Refactor script code and eliminate unneeded whitespace

Refactored and condensed script commands in useful.sh to improve readability and efficiency. Also updated mime encoding format in ContextUtils.php across two repos by removing unnecessary spaces, enhancing data presentation and readability.

lib/classes/Hipot/Utils/ContextUtils.php

@@ -208,7 +208,7 @@ public static function getInlineBase64Image(string $img_file): ?string
 			return null;
 		}
 
-		return 'data: '.mime_content_type($img_file).';base64,'.base64_encode(file_get_contents($img_file));
+		return 'data:'.mime_content_type($img_file).';base64,'.base64_encode(file_get_contents($img_file));
 	}
 
 	/**