[feature] add rate limit middleware (#741)

* feat: add rate limit middleware

* chore: update vendor dir

* chore: update readme with new dependency

* chore: add rate limit infos to swagger.md file

* refactor: add ipv6 mask limiter option

Add IPv6 CIDR /64 mask

* refactor: increase rate limit to 1000

Address https://github.com/superseriousbusiness/gotosocial/pull/741#discussion_r945584800

Co-authored-by: tobi <31960611+tsmethurst@users.noreply.github.com>

vendor/github.com/ulule/limiter/v3/store.go

@@ -0,0 +1,34 @@
+package limiter
+
+import (
+	"context"
+	"time"
+)
+
+// Store is the common interface for limiter stores.
+type Store interface {
+	// Get returns the limit for given identifier.
+	Get(ctx context.Context, key string, rate Rate) (Context, error)
+	// Peek returns the limit for given identifier, without modification on current values.
+	Peek(ctx context.Context, key string, rate Rate) (Context, error)
+	// Reset resets the limit to zero for given identifier.
+	Reset(ctx context.Context, key string, rate Rate) (Context, error)
+	// Increment increments the limit by given count & gives back the new limit for given identifier
+	Increment(ctx context.Context, key string, count int64, rate Rate) (Context, error)
+}
+
+// StoreOptions are options for store.
+type StoreOptions struct {
+	// Prefix is the prefix to use for the key.
+	Prefix string
+
+	// MaxRetry is the maximum number of retry under race conditions on redis store.
+	// Deprecated: this option is no longer required since all operations are atomic now.
+	MaxRetry int
+
+	// CleanUpInterval is the interval for cleanup (run garbage collection) on stale entries on memory store.
+	// Setting this to a low value will optimize memory consumption, but will likely
+	// reduce performance and increase lock contention.
+	// Setting this to a high value will maximum throughput, but will increase the memory footprint.
+	CleanUpInterval time.Duration
+}