Consider caching policies to avoid marshalling every time

[todo]

fabric-peer-ext/pkg/collections/offledger/storeprovider/olstore.go

Lines 258 to 263 in eb44829

	// TODO: Consider caching policies to avoid marshalling every time
	func (s *store) loadPolicy(ns string, config *common.StaticCollectionConfig) (privdata.CollectionAccessPolicy, error) {
	logger.Debugf("[%s] Loading collection policy for [%s:%s]", s.channelID, ns, config.Name)
	colAP := &privdata.SimpleCollection{}
	err := colAP.Setup(config, mspmgmt.GetIdentityDeserializer(s.channelID))

---

This issue was generated by todo based on a TODO comment in eb44829 when #116 was merged. cc @bstasyszyn.