Fix/dev db persistence

[julianochoi]

Description

• Replaces devcontainer services container name to a fixed and simpler name.
• Removes postgres data persistence
• Fixes devcontainer creation being dependent on correct folder naming.
  • Now the devcontainer creation is independent of the workspace folder name on the host.

Related Issue

[Closes/Fixes/Resolves #[issue number]: Describe the related issue that this PR addresses.]

[julianochoi]

To whom it may concern/review:

• clone this repository in folder with different name:
  git clone git@github.com:iaurg/42-transcendence.git test_transcendence
• change to this branch:
  git checkout fix/dev_db_persistence
• Build devcontainer and check if the following are correct:
  • Devcontainer has the repo files.
  • Changing a file in the devcontainer correctly changes in the host.
  • Changing a file in the host correctly changes in the devcontainer.
  • There are no persistent data in the Postgres database after restarting the Postgres container.
• Since the persistence of Postgres was removed, you can remove the postgres folder in the root folder of the repo, if it exists.

NOTE: The folder postgres may have different ownership and may require sudo to remove.