Remove mentioning excluded packages, add indigo framework

[flrdv]

• As some packages were removed from the testsuit, also removed the affiliated code
• Removed mentioning packages in README, that aren't participating in benchmarks
• Removed clevergo package, as it's archived since 2021
• Removed fasthttprouter, as it's officially moved to fasthttp/router
• Added indigo framework
• Slightly updated shell scripts; now each test-*.sh generates graphs automatically, not only test.sh alone