🎁 change clover iiif about > homepage label

Our approach was to edit the source file of clover iiif to change the
label of `"Homepage"` to `"Link to item"`. We also noticed the link
opened within the iFrame creating a nested webpage. So we added a target
parent to the link.

Went into the JavaScript file and searched for `"Homepage"` and replaced
the text with `"Link to item"`.
To fix the nested page we looked for `rw=function` and added
`,target:"_parent"` to the end of the function (after `key:t.id`)

Ref:
- #659