Add Foundry to Precomile-EVM Devcontainer

[martineckardt]

Instead of using Remix in the exercises, let's migrate to foundry and Avalanche CLI to the Precompile-EVM Dev Container, so have a consistent use of tools across all courses

• Add Foundry to Dockerfile, similar to Avalanch Starter Kit
• Add EWOQ Private Key, Foundry to $PATH similar to Avalanche Starter Kit
• Replace instructions from using ANR to Avalanche CLI

[ashucoder9]

#69