[tools] Add d8 tools pki certs check for control-plane certificate expiration inspection

[AmazinMax]

Description

Add d8 tools pki certs check to deckhouse-cli to inspect local control-plane certificate expiration using the go_lib/controlplane expiration API from the companion PR deckhouse/deckhouse#19959.

• registers a new tools -> pki -> certs -> check command tree in d8
• supports full-scan mode for known control-plane PKI artifacts and kubeconfig client certificates
• supports single-file inspection for both PEM certificates and kubeconfig files
• renders kubeadm-like output with separate sections for leaf certificates and certificate authorities
• adds --kubeconfig-dir for non-standard layouts; by default it resolves to the parent directory of --path
• does not restart, reconfigure, or otherwise affect critical cluster components; it only adds a local inspection command to d8

Screenshots

Full scan

Single-file certificate

Single-file kubeconfig (client certificate)

[Copilot]

Pull request overview

This PR adds a new d8 tools pki certs check command subtree to deckhouse-cli to inspect local control-plane PKI and kubeconfig client certificate expiration dates using the github.com/deckhouse/deckhouse/go_lib/controlplane APIs (referenced from the companion Deckhouse PR).

Changes:

• Registers a new tools -> pki -> certs -> check Cobra command tree in d8.
• Implements full-scan and single-file inspection modes, rendering kubeadm-like tables for leaf certs and CAs.
• Adds unit tests for report rendering and core formatting logic, and introduces the go_lib/controlplane dependency (with related dependency bumps).

Reviewed changes

Copilot reviewed 7 out of 8 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
internal/tools/tools.go	Wires the new pki tools subtree into the existing d8 tools command.
internal/tools/pki/cmd/pki.go	Introduces the tools pki command group.
internal/tools/pki/certs/cmd/certs.go	Introduces the tools pki certs command group.
internal/tools/pki/certs/cmd/check.go	Implements certs check CLI flags, modes, and user-facing help/errors.
internal/tools/pki/certs/certs.go	Implements report building (full-scan + single-file) and kubeadm-like rendering.
internal/tools/pki/certs/certs_test.go	Adds test coverage for formatting and report behavior.
go.mod	Adds the controlplane library dependency and bumps several related modules.
go.sum	Records checksum updates for newly added/bumped dependencies.

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