Update balances for holders

[DenisCarriere]

Updates

• ReplacingMergeTree(block_num, is_deleted)
• block_hash EPHEMERAL
• REFRESH AFTER 60 MINUTE for *_holders MV's

Context

This pull request updates the ClickHouse schema for ERC-20 and native token balances to improve deduplication, enable efficient deletion tracking, and add materialized views for quickly accessing top token holders. The main changes are the introduction of an is_deleted column for soft deletion, adjustments to the table engines to support this, and the creation of materialized views for top holders.

Schema enhancements for soft deletion and deduplication:

• Added an is_deleted column (materialized as balance = 0) to both erc20_balances and native_balances tables, enabling efficient tracking of deleted balances. [1] [2]
• Changed the storage engine for both tables to use ReplacingMergeTree with the new is_deleted column as the versioning parameter, improving deduplication and deletion handling. [1] [2]
• Marked the block_hash column as EPHEMERAL in both tables to optimize storage for transient data. [1] [2]

Materialized views for top holders:

• Added a materialized view erc20_balances_holders to track the top 10,000 ERC-20 token holders per contract, refreshing every 60 minutes for up-to-date rankings.
• Added a materialized view native_balances_holders to track the top 100,000 native token holders, also refreshing every 60 minutes.