Migrate Delegate Info to onchain Indentities implimentation.

[roman-opentensor]

DO NOT MERGE until migrate-delegate-identities-onchain is in the subtensor.

This PR covers the issue #2089

This functionality still doesn't exist in the subtensor.

For reproduce it on localnet use the following instruction:

1. Launch local chain with ./scripts/localnet.sh
2. While it is running, bump version in this line by 1 in runtime/src/lib.rs: spec_version: XXX,
3. Build using cargo build --release
4. Open in the browser: https://polkadot.js.org/apps/?rpc=ws%3A%2F%2F127.0.0.1%3A9946#/extrinsics
5. Select Alice in the account
6. Select sudo -> sudoUncheckedWeight in the 2nd line
7. Select system -> setCode in line 3
8. Toggle file upload on the right
9. Drag and drop runtime wasm file to line 4: ./target/release/wbuild/node-subtensor-runtime/target/wasm32-unknown-unknown/release/node_subtensor_runtime.wasm
10. Submit transaction
11. Watch node logs for message Starting migration: set hotkey identities

After these steps code will able to revoke Delegate Indentities from localnet.
NOTE: subtensor has to be created with subtensor = bittensor.subtensor(network="ws://127.0.0.1:9945"). Port could be different.

Check this code execution after steps below.

import bittensor as bt

sub = bt.subtensor(network="ws://127.0.0.1:9945")

for ss58, identity in sub.get_delegate_identities().items():
    print(f">>> {ss58}: {identity}")

[gztensor]

It works, here are additional steps:

For running local subtensor node

The MILLISECS_PER_BLOCK constant under fast-blocks feature needs to change from 250 to 12000 before running it first time to make block time 12 seconds (otherwise runtime upgrade will fail):

/// Fast blocks for development
#[cfg(feature = "fast-blocks")]
pub const MILLISECS_PER_BLOCK: u64 = 250;

Bittensor script for testing

import bittensor as bt

sub = bt.subtensor(network="ws://127.0.0.1:9945")

for ss58, identity in sub.get_delegate_identities().items():
    print(f">>> {ss58}: {identity}")