Fix focusing on editor after leaving the app and returning. More code coverage and removing obsolete bits of code

tests/test_search_edgecase.py

@@ -0,0 +1,15 @@
+from bouquin.search import Search as SearchWidget
+
+
+class DummyDB:
+    def search_entries(self, q):
+        return []
+
+
+def test_make_html_snippet_no_match_triggers_start_window(qtbot):
+    w = SearchWidget(db=DummyDB())
+    qtbot.addWidget(w)
+    html = "<p>" + ("x" * 300) + "</p>"  # long text, no token present
+    frag, left, right = w._make_html_snippet(html, "notfound", radius=10, maxlen=80)
+    assert frag != ""
+    assert left is False and right is True