Extend filecache API (#50)

* Extend filecache API

* Add Repair

Add InvalidationIndex.ResetKey (#48)

Redefine filecache, redesign configs (#47)

* Implement Dumper and Restorer on ShardedMapBy

* Move filecache to generic keys

* Redesign configs

* Redesign configs

* Add blob retention policy

* Update README

* Fix go1.18

* Fix go1.18

Avoid similar name prefixes for filecache blobs (#46)

Add blob abstraction and filecache (#45)

* Add blob abstraction and filecache

* Update README

Add generic implementation with typed keys (#44)

* Add generic implementation with typed keys

* Add generic implementation with typed keys

* Update CI

* Fix go1.18 compat

* Fix flaky test

Fix invalidator for multiple caches with same name (#42)

Add named cache invalidation index (#40)

fix bug in sharded_map_go1.18.go Load method (#39)

Refactor Load/Store as wrappers around Read/Write to enable stats/log…

…s/eviction counters (#38)