Dev/test common updates

[joshLong145]

Description

• Adds dotenv to support for loading ENV vars through a .env
• Adds a Shiva type declaration file
  • Adds type support to local-tests/setup/shiva-client.ts
• Adds a new USE_SHIVA flag to determine if localchain should use shiva or should load the contract context from the networkContext.json

Example of the .env

#Tinny ENV Vars
MAX_ATTEMTPS=1
NETWORK=localchain
DEBUG=true
WAIT_FOR_KEY_INTERVAL=3000
LIT_OFFICAL_RPC=https://chain-rpc.litprotocol.com/http
TIME_TO_RELEASE_KEY=10000
RUN_IN_BAND=true
RUN_IN_BAND_INTERVAL=5000
PRIVATE_KEYS="0x59c6995e998f97a5a0044966f0945389dc9e86dae88c7a8412f4603b6b78690d,0x5de4111afa1a4b94908f83103eb1f1706367c2e68ca870fc3fb9a804cdab365a,0x7c852118294e51e653712a81e05800f419141751be58f605c371e15141b007a6,0x47e179ec197488593b187f80a00eb0da91f1b9d0b13f8733639f19c30a34926a,0x8b3a350cf5c34c9194ca85829a2df0ec3153be0318b5e2d3348e872092edffba,0x92db14e403b83dfe3df233f83dfa3a0d7096f21ca9b0d6d6b8d88b2b4ec1564e,0x4bbbf85ce3377467afe5d46f804f221813b2bb87f24d81f60f1fcdbf7cbf4356,0xdbda1821b80551c9d65939329250298aa3472ba22feea921c0cf5d620ea67b97,0x2a871d0798f97d79848a013d4936a73bf4cc922c825d33c1cf7073dff6d409c6"
NO_SETUP=false
USE_SHIVA=false
NETWORK_CONFIG=./networkContext.json

#Shiva Client ENV Vars
STOP_TESTNET=false
TESTNET_MANAGER_URL=http://0.0.0.0:8000
USE_LIT_BINARIES=true
LIT_NODE_BINARY_PATH=/path/to/lit_node/binary
LIT_ACTION_BINARY_PATH=/path/to/lit_action_binary

[Ansonhkg]

Yes, we need this!