WASHINGTON (Reuters) – Former U.S. President Donald Trump filed a lawsuit on Friday seeking to avoid being compelled to testify or provide any documentation to a congressional panel investigating his supporters’ violent attack on the U.S. Capitol last year. The House committee investigating the attack of Jan. 6, 2021 had unanimously issued a subpoena for the Republican former president to appear on or about Nov. 14. Lawmakers had also extended through this week their initial Nov. 4 deadline for Trump to turn over any related documentation. Representatives for the panel could not be immediately…