allow custom operator

[topshef]

for compatibility with gomint

both buyer and operator would be reserved aliases

map eg operator is 0.0.3203092

to legacy script eg

header dealOperator 0.0.3203092
header network mainnet
display title Yamgo secondary test

#aliases
seller is 0.0.657983
gmcommission is 0.0.260418
collection is 0.0.1034578
spender is 0.0.3203092

#transfers
buyer sends 15 hbar
seller receives 14 hbar
gmcommission receives 1 hbar
seller sends NFT collection-149 to buyer via spender

[topshef]

gm ref https://app.asana.com/0/1203308169191352/1203308169191352/1205111249753708

[topshef]

no code change needed for katomic

just adopt convention that "operator is 0.0.12345" means use that account as the operator

and apply this to deal processors eg https://github.com/topshef/kpos/commit/303b6a8f6382713d0852d96054d7ca62322c5395

[topshef]

enable eg "operator is buyer"