feat: enable single-site license support for multisite

[csemazharul]

This update adds a siteBaseURL variable to manage both single-site and multisite environments. It ensures that all plugins retrieve the correct site URL dynamically, improving consistency across the backend and frontend.

Changes & Implementation:

Added jsConfig variable in backend config file.

'siteBaseURL' => is_multisite() ? network_site_url() : site_url(),

Updated global.d.ts to Include SERVER_VARIABLES Type

declare const SERVER_VARIABLES {
    ....
    siteBaseURL: string;
    ....
}

Updated config.ts to Include SITE_BASE_URL

Added type definition:

interface ConfigType {
  ...
  SITE_BASE_URL: string;
  ...
}

Fetches the value from server variables:

SITE_BASE_URL: getServerVariable('siteBaseURL'),

Note: The file names (config.php, global.d.ts, config.ts, etc.) depend on the specific application structure and use case.