Add the ability to modify a selectKit's content with `replaceContent`
Eg.
```
api.modifySelectKit("combo-box").replaceContent(() => {
return {
id: "foo",
name: "Foo",
};
});
```
will override existing content to only include the passed object
This reverts commit 20780a1eee.
* SECURITY: re-adds accidentally reverted commit:
03d26cd6: ensure embed_url contains valid http(s) uri
* when the merge commit e62a85cf was reverted, git chose the 2660c2e2 parent to land on
instead of the 03d26cd6 parent (which contains security fixes)
Isaac Janzen
Joffrey JAFFEUX
Michael Brown
Jeff Atwood
Robin Ward