tests: standardize naming convention

Use a behavior-driven naming convention for unit tests.

Functions are now named using the pattern: [unit]__[verb]__[scenario]
The __ works as a semantic separator.

Examples:
* jid_create__returns__null_from_null()
* cmd_connect__shows__usage_when_no_server_value

Benefits:
* Easy to find all tests associated with a specific function using the
  mandatory prefix.
* Test output in CI now explicitly describes the unit, the expected
  outcome, and the scenario being tested.

Also disabled keyhandlers tests due to missing code in src/ui.

tests/unittests/tools/test_autocomplete.h

@@ -1,16 +1,21 @@
-void clear_empty(void** state);
-void reset_after_create(void** state);
-void find_after_create(void** state);
-void get_after_create_returns_null(void** state);
-void add_one_and_complete(void** state);
-void add_two_and_complete_returns_first(void** state);
-void add_two_and_complete_returns_second(void** state);
-void add_two_adds_two(void** state);
-void add_two_same_adds_one(void** state);
-void add_two_same_updates(void** state);
-void complete_accented_with_accented(void** state);
-void complete_accented_with_base(void** state);
-void complete_both_with_accented(void** state);
-void complete_both_with_base(void** state);
-void complete_ignores_case(void** state);
-void complete_previous(void** state);
+#ifndef TESTS_TEST_AUTOCOMPLETE_H
+#define TESTS_TEST_AUTOCOMPLETE_H
+
+void autocomplete_complete__returns__null_when_empty(void** state);
+void autocomplete_reset__updates__after_create(void** state);
+void autocomplete_complete__returns__null_after_create(void** state);
+void autocomplete_create_list__returns__null_after_create(void** state);
+void autocomplete_add__updates__one_and_complete(void** state);
+void autocomplete_complete__returns__first_of_two(void** state);
+void autocomplete_complete__returns__second_of_two(void** state);
+void autocomplete_add__updates__two_elements(void** state);
+void autocomplete_add__updates__only_once_for_same_value(void** state);
+void autocomplete_add__updates__existing_value(void** state);
+void autocomplete_complete__returns__accented_with_accented(void** state);
+void autocomplete_complete__returns__accented_with_base(void** state);
+void autocomplete_complete__returns__both_with_accented(void** state);
+void autocomplete_complete__returns__both_with_base(void** state);
+void autocomplete_complete__is__case_insensitive(void** state);
+void autocomplete_complete__returns__previous(void** state);
+
+#endif