.clear command in REPL console

[BenceBakos]

Problem Statement

REPL console can get big over time, hard to search inside with / and ?

Ideas or possible solutions

.clear

I saw a clear() method inside repl.lua, that might be it?
Calling that from my config is equally good, but I guess this might be a usefull feature as well.

[mfussenegger]

Sounds like a good idea - added it in #705

The existing clear method of the repl module could also be used, but it also clears the history.