test: several cleanups for TEST-35-LOGIN

- use test_append_files() to install additional commands
- drop use of expect
- include assert.sh and use assertions at several places
- use timeout command at several places
- always use logind-test-user
- etc

test/test-functions

@@ -1735,16 +1735,6 @@ install_basic_tools() {
     image_install -o sushell
     # in Debian ldconfig is just a shell script wrapper around ldconfig.real
     image_install -o ldconfig.real
-    # for TEST-35-LOGIN
-    image_install -o evemu-device evemu-event crond crontab
-    image_install -o evemu-device evemu-event
-    if command -v expect >/dev/null && command -v tclsh >/dev/null ; then
-        # shellcheck disable=SC2016
-        version="$(tclsh <<< 'puts $tcl_version')"
-
-        image_install expect
-        inst_recursive /usr/lib64/tcl"$version" /usr/share/tcl"$version"
-    fi
 }
 
 install_debug_tools() {