We need a new model for job post promotion that doesn't assume custodial funds

[huumn]

Current job promotion logic assumes a custodial wallet. The costs should probably be paid at one time and count towards a month worth of promotion.

[huumn]

I'm think we reuse boost on the job board:

1. boost lasts 1 month wrt to "promotion status"
2. jobs are ranked boost desc, created_at desc

Also, we improve the boost meaning elsewhere to support ad-like functionality:

1. highest boost in the last month (in a given territory or all territories if we're in home) is pinned to the top
2. boost that isn't the highest in a month otherwise works like normal and ranks higher temporarily