editor: `layout_search_matches` allocates for all ranges

Description

When searching in large documents, e.g. searching for a single letter e will yield a lot of match ranges. layout_search_matches will allocate all of them, even though we can only show the ones that are in the visible range. https://github.com/longbridge/gpui-kit/blob/main/crates/base/src/input/base/element.rs#L800

Proposal

Find the ranges that are visible within the last_layout.visible_range_offset and only allocate and iterate over those instead of all.