[IFramePerspective] It's not possible to set the plugin title

Hi,

It's not possible to set the plugin title as documented on this page: https://bloomreach-forge.github.io/iframe-perspective/install.html (section "Setting Perspective Plugin Title").

The reason seems to be this commit: https://code.onehippo.org/cms-community-dev/hippo-cms/commit/5ad73bf0d2f5d3706e2becadd1639c62a26dd1d2.

The problem is that the new way of setting the title, force us to set a shared title per perspective, instead of a unique title per instance, which is an undesired behavior for a generic perspective like this one, which could potentially be used multiple times on the same project.

Thanks.