chore: validation checks bzz and stewardship

[umerm-work]

Checklist

• I have read the coding guide
• My change requires a documentation update and I have done it
• I have added tests to cover my changes.
• I have filled out the description and linked the related issues

Description

if the reference is incorrect (not 64 or 128 hex characters), return 400
if the reference is correct but not found, then return 404
Remove bzz patch endpoint as it is deprecated.

Closes #1803

Motivation and context (Optional)

Related Issue (Optional)

Screenshots (if appropriate):

---

This change is 

[mrekucci]

Please reflect the API changes also in the openapi specifications.

[umerm-work]

Done

[mrekucci]

Reviewed 5 of 6 files at r1, 2 of 2 files at r3, 5 of 5 files at r4, 2 of 2 files at r5, all commit messages.
Reviewable status: 14 of 15 files reviewed, 2 unresolved discussions (waiting on @umerm-work)

---

pkg/api/stewardship.go line 36 at r5 (raw file):

		s.logger.Debug("stewardship put: service unavailable", "string", nameOrHex, "error", err)
		s.logger.Error(nil, "stewardship put: service unavailable")
		jsonhttp.ServiceUnavailable(w, nil)

This error code can be misleading because it is not clear from the response what service is not available. We also do not try to be specific in the response code. I would suggest returning a simple code 500 with the following message, "stewardship put: resolver service unavailable".

[umerm-work]

Reviewable status: 14 of 15 files reviewed, 1 unresolved discussion (waiting on @agazso and @umerm-work)

---

pkg/api/stewardship.go line 41 at r5 (raw file):

Previously, agazso (Attila Gazso) wrote…

Why do we use a quite obscure HTTP error number (422 Unprocessable Entity) here when there is a simple well-known alternative to it (400 Bad Request)?

As far as I understand we don't even use 422 correctly and that may be also because it's obscure.

The 422 (Unprocessable Content) status code indicates that the server understands the content type of the request content (hence a 415 (Unsupported Media Type) status code is inappropriate), and the syntax of the request content is correct, but it was unable to process the contained instructions. For example, this status code can be sent if an XML request content contains well-formed (i.e., syntactically correct), but semantically erroneous XML instructions.
https://httpwg.org/specs/rfc9110.html#status.422

Done.

[mrekucci]

Reviewed 3 of 3 files at r6, all commit messages.
Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @agazso)