[5.x] Remove manual Glide filenames

[jasonvarga]

Since #9616 appends filenames automatically, there's no need to specify filenames manually anymore.

This was an undocumented relic of a feature that let you add a "fake" or "vanity" filename to the end of Glide URLs to be able to improve SEO. Now that's happening automatically rendering this feature irrelevant. This feature was broken in certain situations anyway, like if you tried to add filename="" to a glide tag where you are passing the path.

This is technically a breaking change since method signatures are changing. Also, you will need to remove filename="" from any glide tags otherwise nothing will be output.