deps: migrate mapstructure to go-viper

[dduzgun-security]

Description

https://github.com/mitchellh/mapstructure is now a public archive, this PR aims to migrate to a fork of it https://github.com/go-viper/mapstructure (v2) which is maintained and gets frequent security patches.

Ref: PSA-2107

Testing & Reproduction steps

Links

PR Checklist

• updated test coverage
• external facing docs updated
• appropriate backport labels added
• not a security concern

PCI review checklist

• I have documented a clear reason for, and description of, the change I am making.

• If applicable, I've documented a plan to revert these changes if they require more than reverting the pull request.

• If applicable, I've documented the impact of any changes to security controls.

  Examples of changes to security controls include using new access control methods, adding or removing logging pipelines, etc.

[sreeram77]

LGTM

[dduzgun-security]

@sreeram77 I've resolved few conflicts with main. Can you re-approve once the CI is green please? I'll merge it after

[hc-github-team-consul-core]

📣 Hi @dduzgun-security! a backport is missing for this PR [22581] for versions [1.18,1.19,1.20,1.21] please perform the backport manually and add the following snippet to your backport PR description:

<details>
	<summary> Overview of commits </summary>
		- <<backport commit 1>>
		- <<backport commit 2>>
		...
</details>

[hc-github-team-consul-core]

📣 Hi @dduzgun-security! a backport is missing for this PR [22581] for versions [1.18,1.19,1.20,1.21] please perform the backport manually and add the following snippet to your backport PR description:

<details>
	<summary> Overview of commits </summary>
		- <<backport commit 1>>
		- <<backport commit 2>>
		...
</details>

[hc-github-team-consul-core]

📣 Hi @dduzgun-security! a backport is missing for this PR [22581] for versions [1.18,1.19,1.20,1.21] please perform the backport manually and add the following snippet to your backport PR description:

<details>
	<summary> Overview of commits </summary>
		- <<backport commit 1>>
		- <<backport commit 2>>
		...
</details>

[hc-github-team-consul-core]

📣 Hi @dduzgun-security! a backport is missing for this PR [22581] for versions [1.18,1.19,1.20,1.21] please perform the backport manually and add the following snippet to your backport PR description:

<details>
	<summary> Overview of commits </summary>
		- <<backport commit 1>>
		- <<backport commit 2>>
		...
</details>

[hc-github-team-consul-core]

📣 Hi @dduzgun-security! a backport is missing for this PR [22581] for versions [1.18,1.19,1.20,1.21] please perform the backport manually and add the following snippet to your backport PR description:

<details>
	<summary> Overview of commits </summary>
		- <<backport commit 1>>
		- <<backport commit 2>>
		...
</details>

[hc-github-team-consul-core]

📣 Hi @dduzgun-security! a backport is missing for this PR [22581] for versions [1.18,1.19] please perform the backport manually and add the following snippet to your backport PR description:

<details>
	<summary> Overview of commits </summary>
		- <<backport commit 1>>
		- <<backport commit 2>>
		...
</details>

[hc-github-team-consul-core]

📣 Hi @dduzgun-security! a backport is missing for this PR [22581] for versions [1.18,1.19] please perform the backport manually and add the following snippet to your backport PR description:

<details>
	<summary> Overview of commits </summary>
		- <<backport commit 1>>
		- <<backport commit 2>>
		...
</details>

[hc-github-team-consul-core]

📣 Hi @dduzgun-security! a backport is missing for this PR [22581] for versions [1.18,1.19] please perform the backport manually and add the following snippet to your backport PR description:

<details>
	<summary> Overview of commits </summary>
		- <<backport commit 1>>
		- <<backport commit 2>>
		...
</details>