Personalize elements should not personalize sets of matched elements

Scenario:

1. User creates a page variation and personalizes a link
2. User then adds content to the page such that a new link is created with the same selector as the one personalized
3. Now when page is personalized, both links are affected and both content is read to generate the control option

Alternate scenario:

1. User creates a page variation
2. User manually edits the selector such that multiple elements are matched
3. Same outcome - personalization attempts are made for all matched elements

Because we cannot know what type of DOM elements are included in the matched elements and whether they can even be treated the same or swapped out, we must default to no personalization - treating it as an error case when multiple elements match the personalized selector.