feat: /accounts/:stake_cred/transactions

[slowbackspace]

prereq blockfrost/blockfrost-utils#64, blockfrost/openapi#423

little speed bump with these indices

CREATE UNIQUE INDE  IF NOT EXISTS bf_u_idx_tx_in_outref_covering
  ON public.tx_in (tx_out_id, tx_out_index)
  INCLUDE (tx_in_id);

CREATE INDEX IF NOT EXISTS bf_idx_tx_out_stakeaddr_covering
  ON public.tx_out (stake_address_id)
  INCLUDE (tx_id, index);

CREATE INDEX IF NOT EXISTS bf_idx_tx_id_covering
  ON public.tx (id)
  INCLUDE (block_id, block_index, hash);

https://explain.dalibo.com/plan/a0e3fe8786f84g10#