Config needs Bidirectional conversions

### Description

Services needs a way to take the configuration and parse it in and out of system file 0.0.121. The format for the file is a protobuf list of `Sting Key -> String Value`. The same as Java properties file.

Today services has a util method `com.hedera.node.config.Utils#networkProperties` that walks the properties but the values are all in object format like `Bytes` or `SemanticVersion` not the String formats like HEX or "1.2.3".

Platform config should provide a built in replace meant to get the map of config pairs to replace `com.hedera.node.config.Utils#networkProperties` also it should provide reverse converters to convert all the values back to strings.