remove accounts cache from basic auth middleware

move cache to ocis-pkg
add password validation cache to accounts service

ocis-pkg/cache/option.go

@@ -0,0 +1,36 @@
+package cache
+
+import "time"
+
+// Options are all the possible options.
+type Options struct {
+	size int
+	ttl  time.Duration
+}
+
+// Option mutates option
+type Option func(*Options)
+
+// Size configures the size of the cache in items.
+func Size(s int) Option {
+	return func(o *Options) {
+		o.size = s
+	}
+}
+
+// TTL rebuilds the cache after the configured duration.
+func TTL(ttl time.Duration) Option {
+	return func(o *Options) {
+		o.ttl = ttl
+	}
+}
+
+func newOptions(opts ...Option) Options {
+	o := Options{}
+
+	for _, v := range opts {
+		v(&o)
+	}
+
+	return o
+}