Solana Indexer DBC pool improvements

[rickyrombo]

• Clamp graduation progress at 1.0
• Remove DBC pool from create coin endpoint
• Track DBC pool using memcmp filters and artist coin base mints
• Track DBC VolatilityTracker (for completeness) and Metrics (for fees)

[raymondjacobson]

we don't use dynamic fees, but i guess we can track this

[raymondjacobson]

oof

[raymondjacobson]

here's an interesting gpt suggestion to avoid magic

package dbc

import (
	"bytes"

	bin "github.com/gagliardetto/binary"
	"github.com/gagliardetto/solana-go"
	"api.audius.co/solana/spl/programs/meteora_dbc"
)

// Mirror exactly the fields that appear BEFORE BaseMint in the on-chain Pool layout.
// IMPORTANT: order and types must match the Borsh schema used on-chain!
type poolPrefixBeforeBaseMint struct {
	VolatilityTracker meteora_dbc.VolatilityTracker
	Config            solana.PublicKey
	Creator           solana.PublicKey
}

func borshSize[T any](v T) int {
	var buf bytes.Buffer
	enc := bin.NewBorshEncoder(&buf)
	_ = enc.Encode(v) // layout is known; errors here would mean schema mismatch
	return buf.Len()
}

var OffsetBaseMintInPool int

func init() {
	const anchorDiscriminatorSize = 8
	OffsetBaseMintInPool = anchorDiscriminatorSize + borshSize(poolPrefixBeforeBaseMint{})
}

[raymondjacobson]

ill open a PR to remove FE

[raymondjacobson]

also not necessary, but doesn't hurt