fix: optimize principal transaction lists and etags

[rafaelcr]

Introduces a new principal_txs table to consolidate and optimize transaction tracking for principals, replacing the old principal_stx_txs table with a more comprehensive solution that allows us to do direct SELECTs instead of calculating data on demand. The old table is kept intact for backwards compatibility.

• Tracks all transaction types (STX, FT, NFT) for principals with detailed event counts and balance tracking. Includes fields for sent/received amounts, balance flags, and event counts for mints, burns, and transfers
• Updated principal activity ETag calculation to correctly handle the new data structure (object with confirmed/mempool properties instead of array)
• Refactored datastore methods to use the new optimized table structure, keeping queries as fast as possible
• Added migration to create the new table and populate it from existing data

[github-actions]

Vercel deployment URL: https://stacks-blockchain-7wae3l55r-hirosystems.vercel.app 🚀

[codecov]

Codecov Report

❌ Patch coverage is 93.54839% with 6 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
...play/parquet-based/importers/new-block-importer.ts	0.00%	5 Missing ⚠️
src/datastore/pg-write-store.ts	98.78%	1 Missing ⚠️

📢 Thoughts on this report? Let us know!

[rafaelcr]

Next step is to perform smoke tests on dev to compare consistency vs prod and check query response times for accounts with large numbers of transactions