add startup message to all plugins

[oxarbitrage]

When running witness_node with different plugins you cant really know as a user in a fast/easy way what plugins were loaded because some have a startup message while others done.
When running with the defaults it is even worst as you don't know what are being actually loaded.

I think all plugins should have a startup message when loaded so the user running the node will know everything goes as expected.

Tasks:

• Define a startup message standard. Can be just {plugin_name} started.
• Add message to all plugins, replace the ones that already have it with new message format.
• Add message to template_plugin.

[xqcool]

add startup message already,but not a good design.look at my branch

[abitmore]

Done?

[jmjatlanta]

Yes, it is done.