Added method to create otc contract

[iamakshat01]

1. 
2. Closes Create an OTC contract #34

[giacomo-cc]

Just tried now and everything seems working fine:

following some consideration:

default values
I would add some default values to the options, we could use the following:

• collateral mint: usdc for mainnet and vyper devUSD (7XSvJnS19TodrQJSbjUR6tEGwmYyL1i9FX7Z5ZQHc53W) for devnet
• default oracle for both switchboard and pyth
• default dates (the most important one): deposit start could be 1h before now(), deposit end 5min after now() and settle start 15min after now()

progress during tx sending
we should provide some feedback to the users for better UX after the tx submit. as of now the screen is stuck for a couple of seconds (ofc depends on the rpc performance, but with public rpcs the magnitude is in terms of 10/20 seconds) and then the ouput with the contract pubkey and the tx sig. We could provide an indeterminate progress bar is there something ready out of the box or simply a console.log with "tx sending" -> "tx confirming" -> "done"

let me know your feedbacks