[gdb/testsuite] Add gdb.tui/wrap-line.exp

[gdb/testsuite] Add gdb.tui/wrap-line.exp

Add a test-case that tests prompt edit wrapping behaviour in the tuiterm, both
for CLI and TUI, both with auto-detected and hard-coded width.

In the CLI case with auto-detected width we run into PR cli/30411, so add a
KFAIL for that failure mode.

Tested on x86_64-linux.