Use TypeaheadFilter with ** operator for project selector search

Separate the ~ (contains) and ** (everywhere/typeahead) operator paths
in NameFilter: ~ keeps single-substring LIKE behavior for explicit
user-facing filters; ** now splits on whitespace and ANDs all tokens,
enabling multi-term search.

Switch SearchableProjectListService from ['name', '~', ...] to
['typeahead', '**', ...] so the project selector routes through
TypeaheadFilter, which inherits the multi-term ** behavior automatically.

Author: wielinde

app/models/queries/projects/filters/name_filter.rb

@@ -39,7 +39,9 @@ def where
       ["LOWER(projects.name) IN (?)", sql_value]
     when "!"
       ["LOWER(projects.name) NOT IN (?)", sql_value]
-    when "~", "**"
+    when "~"
+      ["LOWER(projects.name) LIKE ?", "%#{sql_value}%"]
+    when "**"
       terms = values.first.downcase.split
       conditions = Array.new(terms.size, "LOWER(projects.name) LIKE ?").join(" AND ")
       [conditions, *terms.map { |t| "%#{t}%" }]

frontend/src/app/shared/components/searchable-project-list/searchable-project-list.service.ts

@@ -84,12 +84,12 @@ export class SearchableProjectListService {
         return of([[] as IProject[], searchText, loadingEnabled as boolean, favoriteIds]);
       }
 
-      const nameFilter:ApiV3ListFilter[] = [];
+      const searchFilter:ApiV3ListFilter[] = [];
       if (searchText.length > 0) {
-        nameFilter.push(['name', '~', [searchText]]);
+        searchFilter.push(['typeahead', '**', [searchText]]);
       }
 
-      return this.fetchProjects(nameFilter)
+      return this.fetchProjects(searchFilter)
                  .pipe(map((collection) => [collection._embedded.elements, searchText, loadingEnabled as boolean, favoriteIds]));
     }),
     switchMap(([projects, searchText, loadingEnabled, favoriteIds]:[IProject[],string,boolean,string[]]) => {