Improve test infrastructure

[basfroman]

1. Create a docker image Localnet based on the subtensor/main branch. This will allow running Bittensor master branch tests (which correspond to the release) with mainnet state. We can handle the case when Bittensor release is inconsistent with the main chain. Tests should runs:

• during Bittensor SDK release;
• each night.

2. Nightly tests (cron based) should include 2 types of tests and run:

• Bittensor SDK master based on the subtensor/main docker image;
• Bittensor SDK staging based on the subtensor/devnet-ready docker image;
• every Saturday for non-fast-blocks for staging and master;

Actually, new logic should protect the next cases:

• Subtensor main net update - Bittensor SDK tests based master will be run;
• Subtensor devnet-ready - Bittensor SDK tests based on staging will be run;
• Bittensor SDK release - master tests will be run based on Localnet/main net docker image;
• Bittensor SDK staging based PR - merging branch tests will be run based on Localnet/devnet-ready docker image.

3. Add a GH secret to publish the results of failed tests only to the channel https://discord.com/channels/1359000804123476081/1359003774915575909

• need to create new webhook (“Integrations” → “Webhooks” → “New Webhook”) and add Secret в GitHub

[basfroman]

Need to finish step 3 also