Preset menus are grouped and searchable from the keyboard

Both rule preset menus list presets under the integration or family they belong to, focus their search box as they open and clear it as they close, and let ArrowDown carry on into the list. A rule made from a preset keeps its old name, so existing rules are still recognised.

Both preset menus on the Link Tooltip page were one flat list carrying its grouping as a name prefix, with a search box flush against the menu edge that nothing focused.

Presets carry a menu label and a group built from the integration that owns them; presets that belong to none go under Files or their own label prefix. Opening a menu focuses its search one task later, because ng-bootstrap emits its open event before it focuses its own toggle and before the menu is shown. Closing clears the search, and ArrowDown from the box moves to the first preset that can be picked.

• A rule made from a preset keeps the prefixed name, because that name is how the rule is recognised later and is already sitting in people's rule lists.
• Search requires every typed word to appear somewhere in the preset, which still finds everything the old single-substring filter found.

• Git's group is read from its catalogue label's prefix, because the preset catalogue has no group field.