feat: extend information returned by GET /stamps

[mrekucci]

On top of the current information, the returned data are
extended by: label, depth, amount, bucketDepth,
blockNumber, and immutableFlag.

#1971

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This change is 

[acud]

Looks good!

Reviewed 13 of 13 files at r1.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @mrekucci)

[mrekucci]

@agazso

[janos]

👍

[zelig]

Reviewed 19 of 19 files at r2.
Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @aloknerurkar, @anatollupacescu, and @mrekucci)

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openapi/SwarmCommon.yaml, line 322 at r2 (raw file):

        utilization:
          type: integer
        label:

bucketDepth and timestamp needed too, once indexed stamps PR merged

[mrekucci]

Reviewable status: 2 of 19 files reviewed, 1 unresolved discussion (waiting on @aloknerurkar, @anatollupacescu, and @zelig)

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openapi/SwarmCommon.yaml, line 322 at r2 (raw file):

Previously, zelig (Viktor Trón) wrote…

bucketDepth and timestamp needed too, once indexed stamps PR merged

Done.

[zelig]

Reviewed 19 of 19 files at r3.
Reviewable status: all files reviewed, 2 unresolved discussions (waiting on @aloknerurkar, @anatollupacescu, @mrekucci, and @zelig)

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pkg/api/postage.go, line 107 at r3 (raw file):

	Depth       uint8          `json:"depth"`
	Amount      *bigint.BigInt `json:"amount"`
	BucketDepth uint8          `json:"bucketDepth"`

immutable flag stsill missing

[mrekucci]

Reviewable status: all files reviewed, 2 unresolved discussions (waiting on @aloknerurkar, @anatollupacescu, and @zelig)

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pkg/api/postage.go, line 107 at r3 (raw file):

Previously, zelig (Viktor Trón) wrote…

immutable flag stsill missing

Done.