feat: allow secrets collector to retreive all key data if specified

[diamonwiggins]

Description

This PR adds a new includeAllData field to the secrets collector that allows collecting all key-value pairs from a Kubernetes secret, similar to the existing functionality in the ConfigMap collector.

Problem

Previously, the secrets collector could only:

• Collect secret metadata (existence, basic info)
• Collect a specific key's value using key + includeValue

Users requested the ability to collect all key-value pairs from a secret without having to specify each key individually.

Solution

Added includeAllData boolean field that when set to true:

• Populates a data map with all secret key-value pairs (converted from []byte to string)
• Simplifies logic by making includeAllData take precedence over key-specific collection
• Uses consistent filename patterns (no key suffix when collecting all data)
• Follows the same pattern as the existing ConfigMap collector for consistency

Checklist

• New and existing tests pass locally with introduced changes.
• Tests for the changes have been added (for bug fixes / features)
• The commit message(s) are informative and highlight any breaking changes
• Any documentation required has been added/updated.

Does this PR introduce a breaking change?

• Yes
• No

Usage Examples

# Collect all key-value pairs from a specific secret
- secret:
    name: my-app-config
    namespace: default
    includeAllData: true

# Collect all data from secrets matching a selector
- secret:
    namespace: default
    selector: ["app=my-app"]
    includeAllData: true

Output Format

With includeAllData: true, the JSON output includes a data field:

{
  "namespace": "default",
  "name": "my-app-config", 
  "secretExists": true,
  "data": {
    "database-password": "supersecret123",
    "api-key": "abc123xyz",
    "jwt-secret": "my-signing-key"
  }
}

Traditional key-specific collection remains unchanged:

{
  "namespace": "default",
  "name": "my-app-config",
  "key": "api-key", 
  "secretExists": true,
  "keyExists": true,
  "value": "abc123xyz"
}