Implement Central Registry for Built-in Plugins

[unsuman]

Description

Create a central registry that will manage all internal VM driver plugins. This registry will be instantiated when the program starts and will allow plugins to register themselves by an init() function with a default name and through blank import. The main application will look up plugins and their respective objects by name from this registry(from a map[string]driver.Plugin). The registry should also be responsible for handling plugins(internal and external), in which the priority sequence of the plugins should be selected:

• compiled-in drivers
• drivers located in the same directory as limactl
• drivers located via the PATH directory