Merge pull request #16093 from yuwata/network-htb-add-settings-15213

network: tc: add several settings for HTB

diff --cc man/systemd.network.xml
Simple merge

diff --cc src/network/networkd-network-gperf.gperf
Simple merge

diff --cc test/fuzz/fuzz-network-parser/directives.network
Simple merge

diff --cc test/test-network/systemd-networkd-tests.py
Simple merge