Agent centralized configuration: validate and apply downloaded files

[Nicogp]

Parent issue:

• https://github.com/wazuh/wazuh-agent/issues/32

Description

As part of the development of https://github.com/wazuh/wazuh-agent/issues/32 it is necessary for the module to validate the files received and if they are correct apply the configuration received or restart the agent as needed.

File Reading and Validation:

• The agent must read the configuration files in the specified order.
• The agent must validate each configuration file to ensure it is error-free.

Configuration Application:

• If validation is successful, the agent must apply the new configuration to all relevant modules.
• If required, the agent must be able to restart to apply the new configuration fully.

Other considerations:

• Remove duplicated code.
• Include some useful logs (ie. when the command is not recognized).
• Validate functions pointers (m_setGroupIdFunction, m_getGroupIdFunction, m_downloadGroupFilesFunction).

[Nicogp]

Work update

2024/11/05

• I started to make the changes, added a method in ConfigurationParser to validate files
• I removed the code duplication in CentralizedConfiguration
• Issue on hold due to #256

2024/11/12

• I have taken up the issue
• I added the changes for CentralizedConfiguration to perform the verification of the downloaded files
• I have corrected the creation of the download path for the file
• I have added log messages in case of any failure.

2024/11/19

• Added the changes to move the validated files to the shared folder
• I made a rebasing with master
• I performed manual tests
• I found a bug and corrected it in this PR

2024/11/20

• I have added the changes to moves the valid group file to the 'shared' folder
• I have added the changes to set the SHARED directory in cmake
• I have added the changes to clean up the SHARED directory before downloading new group files

2024/11/21

• I have added the changes to read the shared configuration at agent startup
• I made a PoC to use the observer pattern to notify all subscribing modules that the configuration has changed.

2024/11/22

• I have added the changes to use the observer pattern to notify all subscribing modules that the configuration has changed.
  • I have added the new class
  • I have added the method ReloadConfiguration (empty) to the modules