feat: add run_localnet.sh script

[Thoralf-M]

Add a script to start a localnet with a gas station

Tested with

./run_localnet.sh start
make python-example gas_station
# ./run_localnet.sh logs
./run_localnet.sh stop

Starting local IOTA network with gas station...
Backed up config to ./.github/actions/start-local-network/config.yaml.backup
Starting PostgreSQL...
postgres
Starting IOTA network...
Setting keypair in config...
Waiting for network to start and requesting faucet coins...
Starting Gas Station...
[+] Running 4/4
 ✔ Volume start-local-network_redis_data                                       Created                                                                                                                                                                                0.0s 
 ✔ Container gas-station-redis                                                 Started                                                                                                                                                                                0.2s 
 ✔ Container iota-gas-station                                                  Started                                                                                                                                                                                0.3s 
 ! iota-gas-station Published ports are discarded when using host network mode                                                                                                                                                                                        0.0s 
Waiting for gas station to be ready...
Local network and gas station started successfully!
IOTA PID: 155408
Logs are being written to iota_network.log
To view logs: ./run_localnet.sh logs
To stop, run: ./run_localnet.sh stop

Running Python example "gas_station"
<lib.iota_sdk_ffi.TransactionEffects object at 0x79da05e56bc0>
Sponsored transaction was successful!
Stopping local IOTA network and gas station...
Stopping Gas Station...
OK
[+] Running 2/2
 ✔ Container iota-gas-station   Removed                                                                                                                                                                                                                              10.2s 
 ✔ Container gas-station-redis  Removed                                                                                                                                                                                                                               0.0s 
Removing Redis data volume...
start-local-network_redis_data
Stopping IOTA network...
Stopping PostgreSQL...
postgres
Restored config from backup
Removed log file iota_network.log
Local network and gas station stopped.

Fixes #280

[thibault-martinez]

This doesn't work on macOS but I need it in another PR so I'll merge it an open an issue to investigate