hash_reqs: Use combined package name and version to generate hash.
hash_reqs: Use combined package name and version to generate hash.

We were already using packages names along with their versions
to generate hash for the requirement file, as we were passing
the `.txt` files to the hash_reqs file instead of intended `.in` files
for which the functions in this file was originially designed.

Changed the expand_reqs_helper function to adapt for the `.txt` files.

zulip/zulip,punchagan/zulip,eeshangarg/zulip,eeshangarg/zulip,brainwane/zulip,kou/zulip,eeshangarg/zulip,andersk/zulip,andersk/zulip,showell/zulip,rht/zulip,eeshangarg/zulip,kou/zulip,zulip/zulip,hackerkid/zulip,kou/zulip,rht/zulip,rht/zulip,zulip/zulip,punchagan/zulip,showell/zulip,zulip/zulip,hackerkid/zulip,zulip/zulip,zulip/zulip,andersk/zulip,punchagan/zulip,zulip/zulip,rht/zulip,andersk/zulip,andersk/zulip,rht/zulip,punchagan/zulip,brainwane/zulip,hackerkid/zulip,brainwane/zulip,brainwane/zulip,hackerkid/zulip,punchagan/zulip,punchagan/zulip,showell/zulip,rht/zulip,hackerkid/zulip,hackerkid/zulip,brainwane/zulip,brainwane/zulip,showell/zulip,showell/zulip,andersk/zulip,eeshangarg/zulip,punchagan/zulip,kou/zulip,hackerkid/zulip,eeshangarg/zulip,eeshangarg/zulip,brainwane/zulip,rht/zulip,kou/zulip,kou/zulip,kou/zulip,showell/zulip,andersk/zulip,showell/zulip