feat(RES-57): Add visibility to control scope of generated code (#18)

Add visibility parameter: public, package, internal, private
Impacted command: analytics, colors, fonts, images, strings, tags

Reviewed-on: #18

Sources/ResgenSwift/Fonts/Fonts.swift

@@ -57,7 +57,8 @@ struct Fonts: ParsableCommand {
             staticVar: options.staticMembers,
             extensionName: options.extensionName,
             extensionFilePath: options.extensionFilePath,
-            isSwiftUI: true
+            isSwiftUI: true,
+            visibility: options.extensionVisibility
         )
 
         if let extensionNameUIKit = options.extensionNameUIKit,
@@ -67,7 +68,8 @@ struct Fonts: ParsableCommand {
                 staticVar: options.staticMembers,
                 extensionName: extensionNameUIKit,
                 extensionFilePath: extensionFilePathUIKit,
-                isSwiftUI: false
+                isSwiftUI: false,
+                visibility: options.extensionVisibility
             )
         }