Update method to allow reloading configuration for all plugins with a single call

[bgravenorst]

Extend plugins_reloadplugin method, to make the plugin name parameter optional, and in case it is not passed then all enabled plugins are reloaded.

See: hyperledger/besu#9563

[m4sterbunny]

Note, started 1910-reload-plugins but need #1909 in first to prevent conflicts with api/index page