implement multiplication for polyval

[thor314]

• passing test for gfmulx
• RFC test vector fails
• comments
• refactor test code paths: create dir for gfmulx for polyval and ghash
• implement tests for ghash + format file
• implement polyval tests
• implement more thorough polyval testing to inspect LE encoding bug
• leftshift LE circom written and tested
• incorporate LE shift changes into polyval_GFMULX
• gf_mul polyval passing tests
• note conflict in tests
• implement ghash mulx
• clean
• setup to implement ghash
• impl reverse_byte array
• circomkit bug? can't declare input to GHASH
• ghash tests implemented
• bitreversal test compares output instead of expectPass
• Corrected ghash_gfmul comment
• Added polyval test consistent with ghash
• lint comments in circuit
• impl bmul multiplication subroutine
• impl gfmul (mostly)