[pipes-functions]Adding sha256sum and sums functions

[pratikmota]

Changes:

1. Adding sha256sum function
2. Adding sha256sums function

Testing:

sha256sums function - for verification, i created a local test.txt file and checked.

Doubt:

1. Do we require to use every time pipes/echo ? If i try to use rye .needs { pipes } and then directly echo "hello" then it is not working. Is it correct? or some other way we have to use?
   

2. For all builtins_pipes.go functions, we do not have any unit test cases. Can you suggest me at which place we can add testcase for pipes, if needed? So from next PR i will add unit test cases.

[refaktor]

pipes is it's own context so you can use pipes/echo to call it from outside or move to subcontext in repl (like cd, but cc) uring cc pipes echo "hello" |out. On in code use do\par or do\in do\par pipes { echo "lol" |out }

[refaktor]

Great thanks!