add option for routing_budget_ppm in /api/rewards

[jerryfletcher21]

What does this PR do?

This PR uniforms the /api/rewards with the /api/order update_invoice (changed in #326), adding the option routing_budget_ppm in /api/rewards, and thus fixing #1382 for the backend.
An other pull request implementing it in the frontend is needed (maybe to be incorporated in #1973). This commit still leaves the option to not specify routing_budget_ppm in order to be compatible with old clients, with the notice in the code that it should be deprecated in the future.
It also remove the MIN_FLAT_ROUTING_FEE_LIMIT variable from .env-sample, since after #347 it is no longer used.

Checklist before merging

• Install pre-commit and initialize it: pip install pre-commit, then pre-commit install. Pre-commit installs git hooks that automatically check the codebase. If pre-commit fails when you commit your changes, please fix the problems it points out.

[KoalaSat]

I think it's worth to leave this test as it is and create a new one specifically sending a custom number here

[jerryfletcher21]

added a new test

[KoalaSat]

Thanks again for your continuous support @jerryfletcher21 please accept a small tip for this work. Share here a LN invoice for 30,000 sats with a long expiration date.

[jerryfletcher21]

lnbc300u1p58pew4sp5jrtkmdu69v220qg3lsnqakwe8yg0ed08nw76ur99f6d6rt28jvyqpp5pvtzggquxxz6zcck5sucjxm8h4kqd3wqe5ezak8tkwhtwukxwk2sdqqxq9yn4qqcqzysrzjqdllz2m2fe9ukju5fdkjptcgehlkrv6xrswl7rgq4zrfws2d3yduwr8j0yqpv2sqqqqqqqlgqqqqp9sq2q9qxpqysgqw8j78degc6d628m0t4c2uuk7syzr7mkvwfqyllkj0hq69g0n9nkzwrspwdwq5g2g03ea58c6lwhzhl5jejsvwhwsmwgtlh2skuxfqxgp2h0wvr

[KoalaSat]

72b407ff0918d8a1ef4ffb08b22eb555f74804d9561df13761e28a49bb0a5627

[jerryfletcher21]

@KoalaSat thank you!
I have some old invoices from the times of @Reckless-Satoshi that were not paid, he probably simply forgot, that are now expired.

• improve/update documentation in api/oas_schemas.py #1244
• Return json output instead of html when wrong token in Header Authorization #1247
• add robot status "Seen Recently" where missing in the documentation #1312
• fix warnings DecimalField should be Decimal type #1334
• add lightning protobuf files in gitignore #1342
• remove leftover of avatar generator #1366
• small fix in get_exchange_rates #1365
• add new param current_status to /api/order cancel #1325 (this one I also forgot to send the invoice)

[KoalaSat]

@KoalaSat thank you! I have some old invoices from the times of @Reckless-Satoshi that were not paid, he probably simply forgot, that are now expired.

* [improve/update documentation in api/oas_schemas.py #1244](https://github.com/RoboSats/robosats/pull/1244)

* [Return json output instead of html when wrong token in Header Authorization #1247](https://github.com/RoboSats/robosats/pull/1247)

* [add robot status "Seen Recently" where missing in the documentation #1312](https://github.com/RoboSats/robosats/pull/1312)

* [fix warnings DecimalField should be Decimal type #1334](https://github.com/RoboSats/robosats/pull/1334)

* [add lightning protobuf files in gitignore #1342](https://github.com/RoboSats/robosats/pull/1342)

* [remove leftover of avatar generator #1366](https://github.com/RoboSats/robosats/pull/1366)

* [small fix in get_exchange_rates #1365](https://github.com/RoboSats/robosats/pull/1365)

* [add new param current_status to /api/order cancel #1325](https://github.com/RoboSats/robosats/pull/1325) (this one I also forgot to send the invoice)

Oh! Would you mind to post on each to them a new invoice and tag me? just to keep the record of every payment associated to every PR

[jerryfletcher21]

@KoalaSat

thanks🙏

[KoalaSat]

Thank you!