rework stack management

[errordeveloper]

Description

• cater for dry-run
• cleaner main functions for create and delete commands
• more general abstraction for tasks
• expose all common operations through functions
• remove special purpose functions

Checklist

• Code compiles correctly (i.e make build)
• Added tests that cover your change (if possible)
• All unit tests passing (i.e. make test)
• All integration tests passing (i.e. make integration-test)
• Added/modified documentation as required (such as the README.md, and examples directory)

[errordeveloper]

@rndstr would you mind to take a look at this please?

[errordeveloper]

Still need to rewrite the unit tests.

[errordeveloper]

I think there is a bug, like a possible race condition... I'll need to investigate, perhaps unit tests will show.

[errordeveloper]

@martina-if thanks for spotting the race condition! As I mentioned, I was able to reproduce it with unit tests. I've fixed it a we have quite a few tests now. This PR is in a pretty good shape to merge next week :)

[errordeveloper]

Looks like we cannot use go test -race in alpine container due to CGO/musl:

# runtime/race
/usr/lib/gcc/x86_64-alpine-linux-musl/8.2.0/../../../../x86_64-alpine-linux-musl/bin/ld: race_linux_amd64.syso: in function `__sanitizer::GetArgv()':
gotsan.cc:(.text+0x4183): undefined reference to `__libc_stack_end'
/usr/lib/gcc/x86_64-alpine-linux-musl/8.2.0/../../../../x86_64-alpine-linux-musl/bin/ld: race_linux_amd64.syso: in function `__sanitizer::ReExec()':
gotsan.cc:(.text+0x9797): undefined reference to `__libc_stack_end'
/usr/lib/gcc/x86_64-alpine-linux-musl/8.2.0/../../../../x86_64-alpine-linux-musl/bin/ld: race_linux_amd64.syso: in function `__sanitizer::InternalAlloc(unsigned long, __sanitizer::SizeClassAllocatorLocalCache<__sanitizer::SizeClassAllocator32<__sanitizer::AP32> >*, unsigned long)':
gotsan.cc:(.text+0xaac1): undefined reference to `__libc_malloc'
/usr/lib/gcc/x86_64-alpine-linux-musl/8.2.0/../../../../x86_64-alpine-linux-musl/bin/ld: race_linux_amd64.syso: in function `__sanitizer::InternalRealloc(void*, unsigned long, __sanitizer::SizeClassAllocatorLocalCache<__sanitizer::SizeClassAllocator32<__sanitizer::AP32> >*)':
gotsan.cc:(.text+0xca20): undefined reference to `__libc_realloc'
/usr/lib/gcc/x86_64-alpine-linux-musl/8.2.0/../../../../x86_64-alpine-linux-musl/bin/ld: race_linux_amd64.syso: in function `__sanitizer::InternalFree(void*, __sanitizer::SizeClassAllocatorLocalCache<__sanitizer::SizeClassAllocator32<__sanitizer::AP32> >*)':
gotsan.cc:(.text+0x66e8): undefined reference to `__libc_free'
collect2: error: ld returned 1 exit status