[Grbl_Esp32 PR#590] Suppress one-line case statements and fix atari custom

AllowShortCaseLabelsOnASingleLine: 'true'
It works for simplifying break-only cases, but to me it feels like over-connecting lines.
This configuration runs the following format.
From:
“C++
default:
grblmsgsendf(CLIENT_SERIAL, MsgLevel::Info, "Unknown Switch %d", index);
break;
`
To:
`C++
default: grblmsgsendf(CLIENT_SERIAL, MsgLevel::Info, "Unknown Switch %d", index); break;
“

There seems to be a little bit of a change forgotten in the changes you put in to accommodate the enum class State.
We can keep as much of the original code as possible by adding this fix and then adding a small modification to Atari custom.