Incorrect Bech32 Prefix for script-based DReps

[Ryun1]

OS
Your OS: Unbuntu

Versions
The db-sync version (eg cardano-db-sync --version):
PostgreSQL version: 13.5.0.1

Build/Install Method
The method you use to build or install cardano-db-sync: binaries

Run method
The method you used to run cardano-db-sync (eg Nix/Docker/systemd/none):

Additional context

Problem Report

• drep_hash table view does not reflect different bech32 prefix for script-based DReps
• As per CIP-0005, script based DReps use the prefix of drep_script whereas key based DReps use just drep here

[rdlrt]

The variations in representation is also one of the causes of #1835 request to atleast make bech32 fields optional (there is also draft CIP-105 and CIP-129, that hasnt been merged, but is already been adopted on toolsets mentioned on CIP - I dont expect dbsync to have to keep up with the off-chain formats, as repercussions are historical - and a change 4 years down the line would then require retrofitting fixes to existing records).