reset terminfo: add an empty OSC sequence to rs1 string

In OSC/OTH mode, the parser accumulate bytes until it fills up or
encounters some end-of-osc sequence.
After entering in either of these mode by mistake, for example by
displaying random bytes (e.g. cat a binary) nothing would print anymore
but input would still work.

In that situation, being able to hit `reset` and recover a usable
terminal helps.

You can try with `echo -e '\xc2\x9e'` for PM

kitty/terminfo.py

@@ -227,8 +227,8 @@ string_capabilities = {
     'rmso': r'\E[27m',
     # Exit underline mode
     'rmul': r'\E[24m',
-    # Reset string1
-    'rs1': r'\Ec',
+    # Reset string1 (empty OSC sequence to exit OSC/OTH modes, and regular reset)
+    'rs1': r'\E]\E\\\Ec',
     # Save cursor
     'sc': r'\E7',
     # Set background color