Mock bind program incorrectly declares support for supports_context_header

[Alan-Jowett]

If a program information provider sets supports_context_header then it must allocate a context with the space for this.

Declared here:

ebpf-for-windows/tests/end_to_end/helpers.h

Line 787 in ff0989f

.capabilities = {.supports_context_header = true},

Allocated here:

ebpf-for-windows/tests/end_to_end/helpers.h

Line 723 in ff0989f

bind_md_t* bind_context = reinterpret_cast<bind_md_t*>(ebpf_allocate(sizeof(bind_md_t)));

Due to the mismatch, doing a prog test run using this mock program causes heap corruption.

[shankarseal]

In addition to fixing the test, add a unit test the exercises this code path.