Form to edit or add a single image effect doesn't tell you which style you're in

Problem/Motivation

When adding or editing an image effect, the page with the form doesn't give any indication of which image style this is a part of. The only way of determining this is to look at the URL, which is not good UX.

If an admin is setting up multiple image styles, this can be confusing.

Steps to reproduce

1. Go to admin/config/media/image-styles
2. Create an image style
3. Add an effect. The page title says 'Add Resize effect' (for example) but doesn't tell you which style you're working with
4. Edit the effect. The page title says 'Edit Resize effect' (for example) but doesn't tell you which style you're working with

Proposed resolution

Add the image style name to the page title e.g. 'Edit Resize effect in style STYLENAME'.

Remaining tasks

1 Discuss and approve the title wording.
2 Change the title

User interface changes

Page title changes.

API changes

Data model changes

Release notes snippet