arm-auto-solution/oeqa: Strip ANSI escape sequences

RD-Aspen's shell emits ANSI escape sequences like \x1b[K
when redrawing prompts or cleaning lines, particularly
with longer or wrapped commands. This can cause issues
when parsing output.

This commit adds a regex-based filter in `_process_magic()`
to strip ANSI escape sequences from command output.

Signed-off-by: Ziad Elhanafy <ziad.elhanafy@arm.com>