Merge pull request #6483 from matrix-org/erikj/port_rest_v2

changelog.d/6483.misc

synapse/rest/client/v2_alpha/_base.py

synapse/rest/client/v2_alpha/account.py

synapse/rest/client/v2_alpha/account_data.py

synapse/rest/client/v2_alpha/account_validity.py

synapse/rest/client/v2_alpha/auth.py

synapse/rest/client/v2_alpha/capabilities.py

synapse/rest/client/v2_alpha/devices.py

synapse/rest/client/v2_alpha/filter.py

synapse/rest/client/v2_alpha/groups.py

synapse/rest/client/v2_alpha/keys.py

synapse/rest/client/v2_alpha/notifications.py

synapse/rest/client/v2_alpha/openid.py

synapse/rest/client/v2_alpha/register.py

synapse/rest/client/v2_alpha/relations.py

synapse/rest/client/v2_alpha/report_event.py

synapse/rest/client/v2_alpha/room_keys.py

synapse/rest/client/v2_alpha/room_upgrade_rest_servlet.py

synapse/rest/client/v2_alpha/sendtodevice.py

synapse/rest/client/v2_alpha/sync.py