implement icon cache expiry, cleanup code and upgrade deps

internal/api/v1/favicon/content.go

@@ -0,0 +1,37 @@
+package favicon
+
+import (
+	"bufio"
+	"errors"
+	"net"
+	"net/http"
+)
+
+type content struct {
+	header http.Header
+	data   []byte
+	status int
+}
+
+func newContent() *content {
+	return &content{
+		header: make(http.Header),
+	}
+}
+
+func (c *content) Header() http.Header {
+	return c.header
+}
+
+func (c *content) Write(data []byte) (int, error) {
+	c.data = append(c.data, data...)
+	return len(data), nil
+}
+
+func (c *content) WriteHeader(statusCode int) {
+	c.status = statusCode
+}
+
+func (c *content) Hijack() (net.Conn, *bufio.ReadWriter, error) {
+	return nil, nil, errors.New("not supported")
+}