Improve consistency of example transaction JSON and example transaction queries #3354
Description
As noted in #3328, the example JSON transactions for different transaction types are not very consistent in terms of which common and auto-fillable fields they include.
We would also like to provide queryable examples of every type of transaction that is enabled on Mainnet, using the {% tx-example ... /%} markdoc tag. Example transactions from Devnet for types not enabled on Mainnet are not as useful because Devnet servers generally don't maintain full history and Devnet itself is periodically reset. For example, the example DelegateSet transaction noted in the docs right now returns a not found error because Devnet has been reset since then.
Some types, like the three Check-related ones, have queryable examples but the sample JSON is not complete. Some types are the other way around.