remove user lastActiveTimestamp property

[vincanger]

Description

removes user.lastActiveTimestamp property entirely since we're not really using it in a meaningful way.

Renames updateCurrentUser to a more generic function name in the authorization docs.

Contributor Checklist

Make sure to do the following steps if they are applicable to your PR:

• Update e2e tests: If you changed the /template/app, then make sure to do any neccessary updates to /template/e2e-tests also.
• Update demo app: If you changed the /template/app, then make sure to do any neccessary updates to /opensaas-sh/app_diff also. Check /opensaas-sh/README.md for details.
• Update docs: If needed, update the /opensaas-sh/blog/src/content/docs.

[sodic]

Seems simple enough, approved!

@vincanger You probably did this, but search for lastActiveTimestamp across the entire repo to ensure there are no leftovers.

[sodic]

How come we changed this?

[sodic]

@vincanger I double checked.

We seem to be missing a doc change and a migration for this. Here's how I did it:

$ rg lastActiveTimestamp -l
opensaas-sh/app_diff/migrations/20231213174854_init/migration.sql.diff
opensaas-sh/blog/src/content/docs/general/user-overview.md

[sodic]

Changing PR status until we change the docs and add a migration to avoid accidental merging.

[sodic]

Looks good!