chore: remove unneeded keymanager features

[dracarys18]

Type of Change

• Enhancement

Description

Remove unneeded features related to keymanager

Motivation and Context

This combined multiple feature flags of keymanager into one and also makes keymanager_mtls runtime configurable

How did you test it?

NA

Checklist

• I formatted the code cargo +nightly fmt --all
• I addressed lints thrown by cargo clippy
• I reviewed the submitted code

[semanticdiff-com]

Review changes with  

Changed Files

File	Status
crates/router/src/core/admin.rs	85% smaller
crates/router/src/configs/secrets_transformers.rs	55% smaller
crates/common_utils/src/keymanager.rs	53% smaller
crates/router/src/configs/settings.rs	51% smaller
crates/common_utils/src/lib.rs	50% smaller
crates/router/src/configs/validations.rs	47% smaller
crates/common_utils/src/types/keymanager.rs	41% smaller
crates/common_utils/Cargo.toml	Unsupported file format
crates/common_utils/src/errors.rs	0% smaller
crates/hyperswitch_domain_models/Cargo.toml	Unsupported file format
crates/hyperswitch_domain_models/src/type_encryption.rs	0% smaller
crates/router/Cargo.toml	Unsupported file format
crates/router/src/types/domain/types.rs	0% smaller
crates/router/src/types/domain/user.rs	0% smaller