Added FunctionalApplicationContext.beansOfType with no params

Hi,

If you try to execute `FunctionalConfigApplicationContext.beansOfType` method without empty pair of parentheses, you will get partially applied function instead of map of beans.

    val strings = ctx.beansOfType[String]
    // Compilation error below! 
    // Partially applied function returned instead of Map[String,String].
    strings.size

I think that end-users will execute `ctx.beansOfType[String]` while intending to call `ctx.beansOfType[String]()`. In order to avoid user confusion and provide syntactic sugar, I propose to add overloaded version of the `FunctionalConfigApplicationContext.beansOfType` without a list of parameters.  

    val strings = ctx.beansOfType[String]
    // Compiles, Map[String,String] retrieved.
    strings.size

Cheers.

PS Scaladoc on demand.