Improvement of the manual ad blocker picker

Currently, our tool generates blocking rules starting from more specific selectors and moving toward broader ones. However, these rules are often too tightly bound to the page structure (e.g., element positioning or child counts). As a result, such rules:
- do not transfer well across different pages of the same site,
- require manual adjustments by the user,
- are at risk of breaking when the site’s layout changes.

**Observations:**
- Other products immediately suggest several simple and unambiguous selectors, which usually work across all pages of a site, not just the current one.
- Visual highlighting of the chosen element makes selection much easier and reduces errors.
- Their interfaces include controls that let users gradually adjust the selector from specific to more general in a convenient, visual way.

**Why This Matters:**
- Simplifies the rule selection process for users.
- Produces rules that are more portable and reliable.
- Reduces the number of errors and complaints.
- Improves usability for the active audience that heavily relies on blocking functionality (as seen in community discussions and issue reports).

**Proposed Improvements:**
- Implement element highlighting during selector selection.
- Add a step-by-step tool for simplifying or generalizing a selector (similar to slider controls in other products).
- Prioritize showing simpler and more unambiguous selectors.