Move backend source to server/ subpackage

To clarify the organization.

Cargo.toml

@@ -1,78 +1,6 @@
 [workspace]
-members = [".", "auth", "app"]
-
-[package]
-authors = ["Valentin Tolmer <valentin@tolmer.fr>", "Steve Barrau <steve.barrau@gmail.com>", "Thomas Wickham <mackwic@gmail.com>"]
-edition = "2018"
-name = "lldap"
-version = "0.1.0"
-
-[dependencies]
-actix = "0.12"
-actix-files = "0.6.0-beta.6"
-actix-http = "3.0.0-beta.9"
-actix-rt = "2.2.0"
-actix-server = "2.0.0-beta.5"
-actix-service = "2.0.0"
-actix-web = "4.0.0-beta.8"
-actix-web-httpauth = "0.6.0-beta.2"
-anyhow = "*"
-async-trait = "0.1"
-base64 = "0.13"
-bincode = "1.3"
-chrono = { version = "*", features = [ "serde" ]}
-clap = "3.0.0-beta.2"
-cron = "*"
-derive_builder = "0.10.2"
-futures = "*"
-futures-util = "*"
-hmac = "0.10"
-http = "*"
-jwt = "0.13"
-ldap3_server = "*"
-lldap_auth = { path = "auth" }
-log = "*"
-orion = "0.16"
-serde = "*"
-serde_json = "1"
-sha2 = "0.9"
-sqlx-core = "=0.5.1"
-thiserror = "*"
-time = "0.2"
-tokio = { version = "1.2.0", features = ["full"] }
-tokio-util = "0.6.3"
-tracing = "*"
-tracing-actix-web = "0.4.0-beta.7"
-tracing-log = "*"
-tracing-subscriber = "*"
-rand = { version = "0.8", features = ["small_rng", "getrandom"] }
-juniper_actix = "0.4.0"
-juniper = "0.15.6"
-
-# TODO: update to 0.6 when out.
-[dependencies.opaque-ke]
-git = "https://github.com/novifinancial/opaque-ke"
-rev = "eb59676a940b15f77871aefe1e46d7b5bf85f40a"
-
-[dependencies.sqlx]
-version = "0.5.1"
-features = [
-  "any",
-  "chrono",
-  "macros",
-  "mysql",
-  "postgres",
-  "runtime-actix-native-tls",
-  "sqlite",
+members = [
+  "server",
+  "auth",
+  "app"
 ]
-
-[dependencies.sea-query]
-version = "0.9.4"
-features = ["with-chrono"]
-
-[dependencies.figment]
-features = ["env", "toml"]
-version = "*"
-
-[dev-dependencies]
-mockall = "0.9.1"