add Redis cache and some clean up

- update and cleanup in README.md
- update getIdentity to throw response exception with 401 in JwtService
- update http files to use identity from env
- add cacheable to getIdentityFromDevice in DeviceRegistryService
- add RedisCacheConfiguration
- add CacheProperty
- set up cache property
- set up data redis cache

src/main/kotlin/ltd/hlaeja/Application.kt

@@ -1,5 +1,6 @@
 package ltd.hlaeja
 
+import ltd.hlaeja.property.CacheProperty
 import ltd.hlaeja.property.DeviceConfigurationProperty
 import ltd.hlaeja.property.DeviceDataProperty
 import ltd.hlaeja.property.DeviceRegistryProperty
@@ -7,8 +8,11 @@ import ltd.hlaeja.property.JwtProperty
 import org.springframework.boot.autoconfigure.SpringBootApplication
 import org.springframework.boot.context.properties.EnableConfigurationProperties
 import org.springframework.boot.runApplication
+import org.springframework.cache.annotation.EnableCaching
 
+@EnableCaching
 @EnableConfigurationProperties(
+    CacheProperty::class,
     DeviceConfigurationProperty::class,
     DeviceDataProperty::class,
     DeviceRegistryProperty::class,