Redis configuration provider

[apemaia99]

Redis

• This PR aims to solve the impossibility to use the package without dependencies in unit test environments.
• RedisFactory is a protocol that defines how to produce RedisClients.
• RedisConfigurationFactory is an abstract factory that produce RedisConfigurations, and provides several methods that replaces all RedisConfiguration constructors. This breaks current APIs
• An instance of redis now can be configured as following:
• • try app.redis(.one).use(.standalone(hostname: "an-hostname", port: 6379, pool: .init(connectionRetryTimeout: .milliseconds(100)))) like we already do in Fluent.
• RedisConfiguration conforms to RedisFactory and actually creates RedisClients where previously were done in RedisStorage.LifeCycle.
• RedisStorage now stores RedisClient instead of RedisConnectionPool.
• • the only way to use func withBorrowedConnection is by down casting RedisClient to RedisConnectionPool with as? operator or an error will be trowed.
• The package expose also another product XCTRedis similarly to XCTFluent
• Some file/folder & code refactor.

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XCTRedis

This product allows to stub responses of redis, also for PubSub in order to test applications without conditions in production code to exclude redis. Writing code for test is not the way.

• ArrayTestRedisClient is a stub class for storing & manipulating responses.
• • User shall interact with this class like XCTFluent ArrayTestDatabase
• DummyRedis is the actual RedisClient stored in RedisStorage during tests.
• • These instances are as many as the eventLoops of our application.
• • Each instance peek responses from same ArrayTestRedisClient
• RedisStub is the actual factory to be used in tests.
• • app.redis(.one).use(.stub(client: client))

Redis configuration provider + XCTRedis