Change HomeServer definition to work with typing.

Duplicating function signatures between server.py and server.pyi is
silly. This commit changes that by changing all `build_*` methods to
`get_*` methods and changing the `_make_dependency_method` to work work
as a descriptor that caches the produced value.

There are some changes in other files that were made to fix the typing
in server.py.

1 files changed, 1 insertions, 0 deletions

diff --git a/tox.ini b/tox.ini

index 9a052c1e33..7971a7f9a8 100644
--- a/tox.ini
+++ b/tox.ini
@@ -202,6 +202,7 @@ commands = mypy \
             synapse/push/push_rule_evaluator.py \
             synapse/replication \
             synapse/rest \
+            synapse/server.py \
             synapse/server_notices \
             synapse/spam_checker_api \
             synapse/storage/databases/main/ui_auth.py \