Tx pool output temporary cache (#2802)

## Linked Issues/PRs
Resolves #2801

## Description
- Add a new cache with outputs extracted from the pool for the duration
of the block.
- Change new txs notifier to be notified only on executable transactions

## Checklist
- [x] Breaking changes are clearly marked as such in the PR description
and changelog
- [x] New behavior is reflected in tests
- [x] [The specification](https://github.com/FuelLabs/fuel-specs/)
matches the implemented behavior (link update PR if changes are needed)

### Before requesting review
- [x] I have reviewed the code myself
- [x] I have created follow-up issues caused by this PR and linked them
here

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Co-authored-by: Green Baneling <XgreenX9999@gmail.com>