remove clap as a parser for echo flags as it creates problems with hyphens

[cerdelen]

Dealing with hyphen errors in another issue it was found that clap seems to be the root of multiple erroneous interaction with arguments with hyphens and flags to echo.

issue: #7558
Implementation attempts #7559 , #7581

It seems that parsing flags manually without the help of Clap might help get rid of those errors and also would also make the clap dependency redundant?

[cerdelen]

I am trying to work on a solution on my fork and have the current test suite running green but unfortunately 1 test case that we found in the other issues is still red

-n -e -- 'foo\n'

[cakebaker]

#7352 might be helpful, it removed clap from expr.