[WIP] Updated ListAssetRequest to include additional filter options

[itsrachelfish]

Resolves #876

Been discussing the architecture for this with @GeorgeTsagk. Currently this PR just adds an additional option to filter by minAmount. Next steps are to refactor fetchRpcAssets to accept a single AssetQueryFilters argument instead of separate arguments for each filter option.

Fortunately the assets SQL file already includes QueryAssetsParams which can be used to provide all of the necessary filter options except for maxAmount. This will also need to be updated.

taproot-assets/tapdb/sqlc/assets.sql.go

Lines 2279 to 2293 in ee06af7

	type QueryAssetsParams struct {
	AssetIDFilter []byte
	TweakedScriptKey []byte
	AnchorPoint []byte
	Leased interface{}
	Now sql.NullTime
	MinAnchorHeight sql.NullInt32
	MinAmt sql.NullInt64
	Spent sql.NullBool
	KeyGroupFilter []byte
	AnchorUtxoID sql.NullInt64
	GenesisID sql.NullInt64
	ScriptKeyID sql.NullInt64
	Bip86ScriptKeysOnly bool
	}