dashboard, p2p, vendor: visualize peers (#19247)

* dashboard, p2p: visualize peers

* dashboard: change scale to green to red

vendor/github.com/oschwald/maxminddb-golang/mmap_unix.go

@@ -0,0 +1,15 @@
+// +build !windows,!appengine
+
+package maxminddb
+
+import (
+	"golang.org/x/sys/unix"
+)
+
+func mmap(fd int, length int) (data []byte, err error) {
+	return unix.Mmap(fd, 0, length, unix.PROT_READ, unix.MAP_SHARED)
+}
+
+func munmap(b []byte) (err error) {
+	return unix.Munmap(b)
+}