Add functionality to set text for input node

[kerabromsmu]

Added the set_text parameter to dirtylarry:input() method. If this parameter is set (i.e. not nil), then the text on the input field is set to this parameter's value. Passing an empty string will set the input field to empty. Type of value is not checked.

[kerabromsmu]

Hello! It's been a while since I made this PR. Would you accept or decline it?

[andsve]

Hey! Sorry for the late reply, been on vacation!

I'm thinking if it actually should be a separate function, like;

dirtylarry:set_input_text("input_node", "replacement text")

Mostly since it might be confusing to set/reset text of an input using the "handle input" function. Then it would be possible to set the text of a input node without the need to run all the input handling code as well. Like;

dirtylarry:button("clear_button", action_id, action, function()
    dirtylarry:set_input_text("input_node", "")
end)

On the other hand, this might be a bit against the imgui-ish style of dirtylarry...
But I'm not sure, it might make sense to actually have both options, what do you think?

I love that you want to contribute! ❤️