[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/options.go

@@ -0,0 +1,61 @@
+package limiter
+
+import (
+	"net"
+)
+
+// Option is a functional option.
+type Option func(*Options)
+
+// Options are limiter options.
+type Options struct {
+	// IPv4Mask defines the mask used to obtain a IPv4 address.
+	IPv4Mask net.IPMask
+	// IPv6Mask defines the mask used to obtain a IPv6 address.
+	IPv6Mask net.IPMask
+	// TrustForwardHeader enable parsing of X-Real-IP and X-Forwarded-For headers to obtain user IP.
+	// Please be advised that using this option could be insecure (ie: spoofed) if your reverse
+	// proxy is not configured properly to forward a trustworthy client IP.
+	// Please read the section "Limiter behind a reverse proxy" in the README for further information.
+	TrustForwardHeader bool
+	// ClientIPHeader defines a custom header (likely defined by your CDN or Cloud provider) to obtain user IP.
+	// If configured, this option will override "TrustForwardHeader" option.
+	// Please be advised that using this option could be insecure (ie: spoofed) if your reverse
+	// proxy is not configured properly to forward a trustworthy client IP.
+	// Please read the section "Limiter behind a reverse proxy" in the README for further information.
+	ClientIPHeader string
+}
+
+// WithIPv4Mask will configure the limiter to use given mask for IPv4 address.
+func WithIPv4Mask(mask net.IPMask) Option {
+	return func(o *Options) {
+		o.IPv4Mask = mask
+	}
+}
+
+// WithIPv6Mask will configure the limiter to use given mask for IPv6 address.
+func WithIPv6Mask(mask net.IPMask) Option {
+	return func(o *Options) {
+		o.IPv6Mask = mask
+	}
+}
+
+// WithTrustForwardHeader will configure the limiter to trust X-Real-IP and X-Forwarded-For headers.
+// Please be advised that using this option could be insecure (ie: spoofed) if your reverse
+// proxy is not configured properly to forward a trustworthy client IP.
+// Please read the section "Limiter behind a reverse proxy" in the README for further information.
+func WithTrustForwardHeader(enable bool) Option {
+	return func(o *Options) {
+		o.TrustForwardHeader = enable
+	}
+}
+
+// WithClientIPHeader will configure the limiter to use a custom header to obtain user IP.
+// Please be advised that using this option could be insecure (ie: spoofed) if your reverse
+// proxy is not configured properly to forward a trustworthy client IP.
+// Please read the section "Limiter behind a reverse proxy" in the README for further information.
+func WithClientIPHeader(header string) Option {
+	return func(o *Options) {
+		o.ClientIPHeader = header
+	}
+}