Replace SHA1 Implementation
Motivation: The `CNIOSHA1` module from SwiftNIO is an implementation detail. The fact that we were able to import and build the project with it is a bug/feature of Swift Package Manager. Should the Swift ecosystem standardize on an implementation, that will replace the one we have chosen later. Modifications: Use the SHA1 native Swift implementation from CryptoSwift by reproducing the necessary code in our project. Updates to the appropriate files to provide attribution to CryptoSwift have been included. Result: A reliable and pure Swift implementation of the SHA1 digest algorithm in the project for the sake of Lua script cache hashing.