No replace mode, specific erase.

[Pilihp64]

The ctrl-alt selection of elements and replace mode in normal tpt are not very intuitive, it needs a better solution.
And because there is no third selected element right now, there can't be replace mode.

Specific erase is kind of pointless, and is more of just replacing with erase tool, but I thought I should mention it as well.

[simtr]

In TPT++, there are 3 current elements, Left (Defaults to DUST), Middle (No default, but will default to a sample tool in the future) and Right (Defaults to erase). I'm not sure how to approach specific erase and replace mode.