Implementation of metadata-based freshness

[mikealfare]

resolves #615

Problem

The current implementation of source freshness requires querying the data and requires the user provide a datetime field. This is slower and more expensive than it should be. It doesn't scale across multiple models. And some models do not have an appropriate datetime field.

Solution

Use source metadata where available.

Checklist

• I have read the contributing guide and understand what's expected of me
• I have run this code in development and it appears to resolve the stated issue
• This PR includes tests, or tests are not required/relevant for this PR
• This PR has no interface changes (e.g. macros, cli, logs, json artifacts, config files, adapter interface, etc) or this PR has already received feedback and approval from Product or DX

[github-actions]

The backport to 1.7.latest failed:

The process '/usr/bin/git' failed with exit code 1

To backport manually, run these commands in your terminal:

# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add .worktrees/backport-1.7.latest 1.7.latest
# Navigate to the new working tree
cd .worktrees/backport-1.7.latest
# Create a new branch
git switch --create backport-694-to-1.7.latest
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 d77f5ee9561bf11eae56b2832340e3c11005b6f9
# Push it to GitHub
git push --set-upstream origin backport-694-to-1.7.latest
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-1.7.latest

Then, create a pull request where the base branch is 1.7.latest and the compare/head branch is backport-694-to-1.7.latest.