allow panel wise configurations

[iliyas-inode]

With this PR, now this plugin can have different configurations for each panels. by default this will get config values from global config file. However we can override those config panel wise while declaring plugin for each panel.

For example, we can config flag/native/locales for particular panel only using

FilamentLanguageSwitchPlugin::make()
    ->native()
    ->flag()
    ->locales(['en', 'hi', 'ta'])

[bezhanSalleh]

thanks. and check in #57