Implement system.dns_cache table

[allmazz]

Changelog category (leave one):

• New Feature

Changelog entry (a user-readable short description of the changes that goes to CHANGELOG.md):

Implemented system.dns_cache table, which can be useful for debugging DNS issues

Closes #42690

Example usage: SELECT * FROM system.dns_cache;

hostname	ip_address	ip_family	cached_at
localhost	::1	IPv6	2024-02-11 16:08:16
localhost	127.0.0.1	IPv4	2024-02-11 16:08:16

Documentation entry for user-facing changes

• Documentation is written (mandatory for new features)

Information about CI checks: https://clickhouse.com/docs/en/development/continuous-integration/

[CLAassistant]

All committers have signed the CLA.

[robot-ch-test-poll4]

This is an automated comment for commit 59c40bc with description of existing statuses. It's updated for the latest CI running

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Check name	Description	Status
AST fuzzer	Runs randomly generated queries to catch program errors. The build type is optionally given in parenthesis. If it fails, ask a maintainer for help	❌ failure
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[alexey-milovidov]

Please sign a CLA.

[allmazz]

Please sign a CLA.

Done

[alexey-milovidov]

The test has failed. Please resubmit.

[rschu1ze]

This should really be of type Enum.

Alternatively, replace ip_address by ipv4 (of type Nullable([IP4](https://clickhouse.com/docs/en/sql-reference/data-types/ipv4)), ipv6 (of type Nulalble(IP6)) and unix_local (of type String)

[allmazz]

thx, it's done

[allmazz]

new PR #60257