move req files to new dir

[sssoleileraaa]

Description

Move requirement file into a requirements directory

Test Plan

0. delete or .venv

1. run make venv

   • verify that you see: venv.txt

2. activate the newly created environment: source .venv/bin/activate

3. run the client

   • confirm that you see login window

4. run make safety

   • verify that you see: safety.txt

5. run make update-pip-requirements

   • verify that you see: update-pip-requirements.txt

6. run make update-mac-pip-requirements

   • verify that you see the same results as you do on main branch (i will confirm if you don't have a mac - just let me know)

7. build a debian package from the update-client-reqs-location packaging branch that supports a requirements directory (see support building projects with a requirments dir securedrop-builder#183):

   • package builds without error
   • run that package and confirm that you see login window

Checklist

• Once support building projects with a requirments dir securedrop-builder#183 is merged verify that ci passes here
• I have tested these changes in the appropriate Qubes environment
• No update to the AppArmor profile is required for these changes
• No database schema changes are needed

[kushaldas]

Rebased, I will formally approve after the CI is green, all test steps worked locally.

[kushaldas]

This is good. 🦄