databroker: refactor databroker to sync all changes (#1879)

* refactor backend, implement encrypted store

* refactor in-memory store

* wip

* wip

* wip

* add syncer test

* fix redis expiry

* fix linting issues

* fix test by skipping non-config records

* fix backoff import

* fix init issues

* fix query

* wait for initial sync before starting directory sync

* add type to SyncLatest

* add more log messages, fix deadlock in in-memory store, always return server version from SyncLatest

* update sync types and tests

* add redis tests

* skip macos in github actions

* add comments to proto

* split getBackend into separate methods

* handle errors in initVersion

* return different error for not found vs other errors in get

* use exponential backoff for redis transaction retry

* rename raw to result

* use context instead of close channel

* store type urls as constants in databroker

* use timestampb instead of ptypes

* fix group merging not waiting

* change locked names

* update GetAll to return latest record version

* add method to grpcutil to get the type url for a protobuf type

internal/testutil/testdata/create_test_cert.sh

@@ -0,0 +1,27 @@
+#!/bin/bash
+
+#!/bin/bash
+mkdir -p tls
+openssl genrsa -out tls/ca.key 4096
+openssl req \
+    -x509 -new -nodes -sha256 \
+    -key tls/ca.key \
+    -days 3650 \
+    -subj '/O=Redis Test/CN=Pomerium CA' \
+    -out tls/ca.crt
+openssl genrsa -out tls/redis.key 2048
+openssl req \
+    -new -sha256 \
+    -key tls/redis.key \
+    -subj '/O=Redis Test/CN=Server' | \
+    openssl x509 \
+        -req -sha256 \
+        -CA tls/ca.crt \
+        -CAkey tls/ca.key \
+        -CAserial tls/ca.txt \
+        -CAcreateserial \
+        -days 3650 \
+        -out tls/redis.crt \
+        -extensions san \
+        -extfile tls/req.conf
+openssl dhparam -out tls/redis.dh 2048