[Fix] Savers endpoints

• Add savers info for each L1 pool directly on the pools response

E.g.:

{
	"LP_units": "100000000000",
	"asset": "BNB.BNB",
	"balance_asset": "500000000",
	"balance_rune": "71938775550",
	"pending_inbound_asset": "0",
	"pending_inbound_rune": "0",
	"pool_units": "113953488295",
	**"savers_units": "122448979",** // Equals `lp_units` of the underlying savers vault
	**"savers_depth": "122448979",** // Equals `balance_asset` of the underlying savers vault
	"status": "Available",
	"synth_supply": "122448979",
	"synth_units": "13953488295"
}