Major example update

- Increased example modularization by moving the majority
  of app logic inside dedicated modules
- Added a new `dyn_tmtc` feature for the satrs-example which is used
  to configure the heap as the backing store for TMTC packages instead
  of static stores.
- Added dedicated satrs-example chapter in satrs-book

satrs-example/src/bin/simpleclient.rs

@@ -5,7 +5,7 @@ use satrs_core::{
     spacepackets::ecss::{PusPacket, WritablePusPacket},
     spacepackets::SpHeader,
 };
-use satrs_example::{OBSW_SERVER_ADDR, SERVER_PORT};
+use satrs_example::config::{OBSW_SERVER_ADDR, SERVER_PORT};
 use std::net::{IpAddr, SocketAddr, UdpSocket};
 use std::time::Duration;