kvserver: add leases.requests.latency metric

[erikgrinaker]

This patch adds a histogram of lease request latencies. It includes all request types (acquisitions, transfers, and extensions) and all outcomes (successes and errors), but only considers the coalesced lease requests regardless of the number of waiters and how long they have been waiting for.

Epic: none
Release note (ops change): Added a metric leases.requests.latency recording a histogram of lease request latencies.

[blathers-crl]

It looks like your PR touches production code but doesn't add or edit any test code. Did you consider adding tests to your PR?

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[cockroach-teamcity]

This change is 

[andrewbaptist]

Note that you need to update the chart_catalog also to get this to be mergeable (or wait for Tobi to delete it).

[erikgrinaker]

bors r+

[craig]

Build failed:

• Bazel Essential CI (Cockroach)

[erikgrinaker]

bors retry

[craig]

Build failed:

• Bazel Essential CI (Cockroach)

[erikgrinaker]

bors retry

[craig]

Build failed:

• Bazel Essential CI (Cockroach)

[erikgrinaker]

bors retry

[craig]

Build failed:

• Bazel Essential CI (Cockroach)

[erikgrinaker]

bors retry

[craig]

Build failed (retrying...):

• Bazel Essential CI (Cockroach)

[craig]

Build failed:

• Bazel Essential CI (Cockroach)

[erikgrinaker]

bors retry

[craig]

Build succeeded:

• Bazel Essential CI (Cockroach)

[blathers-crl]

Encountered an error creating backports. Some common things that can go wrong:

1. The backport branch might have already existed.
2. There was a merge conflict.
3. The backport branch contained merge commits.

You might need to create your backport manually using the backport tool.

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error creating merge commit from 0c41a7e to blathers/backport-release-22.1-100287: POST https://api.github.com/repos/cockroachdb/cockroach/merges: 409 Merge conflict []

you may need to manually resolve merge conflicts with the backport tool.

Backport to branch 22.1.x failed. See errors above.

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