Change `example_crates`'s output format to be JSON

[nymius]

Describe the enhancement
Change all the example_crates output format to be JSON.

Use case
Easier output information extraction through jq tool, for better integration with shell script or other external cli tools.

Additional context
I have been using heavily the example_crates to test some workflows, mainly written as shell scripts or similar.
The problem is I find more intuitive to extract information from JSON using jq than use regex to extract the same information from strings.
There are any concerns about changing all the example_crates output format to be in JSON?
Is this change behind the scope of the example_crates or it is a legit enhancement?
May this break the development workflow of anyone testing things with example_crates too?

[sudo-rsingh]

@nymius hey can you pls assign this issue to me?

[nymius]

Hello @sudo-rsingh, notice here I was seeking for feedback about the justifiability of the change. The project can decide this is not necessary or it breaks some workflow, and not merge it at the end, but I think is something trivial, so go ahead and start working on it if you want.

[SharanRP]

Hello @nymius
I have submitted PR #1920, which implements the changes to enable this feature on example_wallet_rpc. Could you please review the modifications ?

[luisschwab]

Agree, this would be useful.

[LLFourn]

I think this would be a good idea. I'd start by structuring the output for each command into types. Then have a -j flag that outputs everything in json. If -j isn't specified it should just be human friendly.

There are a few example crates that stream output at they go I suppose they can be changed to make all that go to stderr.