chore: deprecate beaker template with explicit question + warning & exit task

[aorumbayev]

Proposed Changes

Slightly different approach to deprecation warning on beaker template:

• Reuses approach with custom tasks from fullstack template
• • A dedicated post_init.py script which takes care of deleting cloned template content (copier has limitation in regards to only running tasks after template is instantiated)
• • Covers edge cases when init is done in workspaces vs no workspace mode
• • Covers edge cases when init is run from algokit binary where we need to use pre bundled python instead given that a user may not have python installed

[aorumbayev]

@lempira i did a test on windows vm with a wheel based algokit, but would suggest doing an extra sanity check on algokit binary on windows/unix and wheel based algokit on windows. Windows is often full of surprises - although i don't anticipate any issues with this.

You can quickly test it with command below, an explicit question on whether to proceed with deprecated template or not will be asked to user before any other copier questions on the template. If user says NO (which is the default) -> post init script will revert everything and print instructions suggesting to use python template.
algokit -v init --template-url=https://github.com/algorandfoundation/algokit-beaker-default-template --template-url-ref=deprecate-template-v2

If you are ok with the approach, feel free to merge to your branch and then squash merge to main (ill pre approve your pr), also please add chore: to the merge commit message title to ensure semantic release is properly dumped on releases page on the repo.

[aorumbayev]

@lempira i see you migrated some of the changes from this branch directly, so closing the pr