Lock the default share message on Social Share Campaigns

As an admin, you can now control whether or not the share message on a share campaign should be editable by your members.

- When editability is turned off, and you haven't provided a default message, members won't be able to add a message to the share, and it will be shared without a message.

- When editability is turned off, and you've provided a single default message, this message will be used when sharing. Members won't be able to make changes to it.

- When editability is turned off, and you've provided more than one default message, members can still choose which one they want to use but won't be able to make changes to it.

Just so you know, this is only relevant to channels that support API share, as we cannot control the share message in other scenarios.