feat(p2pool): fixed share chain synchronization and applied strongest…

… chain consensus rules (#19)

Description
---
Synchronization was unstable and random, so I fixed it by applying the
longest (strongest) chain consensus rules on share chain blocks and
fixed logic when and what to sinchronize.

Motivation and Context
---

How Has This Been Tested?
---
Firstly I ran locally 2 separate p2pool nodes with 2 separate miners on
2 different wallet addresses.
Then disabled mDNS on both of the nodes and used a test node as
bootstrap node for both of them and run mining again.
Lastly I tested with @therealdannzor with the same test node as
bootstrap.

All the cases were working fine and I was able to mine blocks together
with pool members.

What process can a PR reviewer use to test or verify this change?
---
Start 2 p2pool nodes locally and start 2 miners on both of them and see
the new mined rewards coming after some time.


Breaking Changes
---

- [x] None
- [ ] Requires data directory on base node to be deleted
- [ ] Requires hard fork
- [ ] Other - Please specify

.github/workflows/ci.yml

@@ -167,8 +167,6 @@ jobs:
       matrix:
         tari_target_network: [
           { target: "testnet", network: "esmeralda" },
-          { target: "nextnet", network: "nextnet" },
-          { target: "mainnet", network: "stagenet" },
         ]
     env:
       TARI_TARGET_NETWORK: ${{ matrix.tari_target_network.target }}