Add allocated_time columns for low-res and mid-res separately

As we ask users to fill the observing time request for low-resolution and medium-resolution modes separately, I'd like to modify the contents of the proposal table in the targetdb as follows.

Current columns

• proposal_id
• group_id
• pi_first_name
• pi_last_name
• pi_middle_name
• rank
• grade
• allocated_time
• proposal_category_id
• created_at
• updated_at

Add

• allocated_time_lowres
• allocated_time_midres (medres?)

Rename

• allocated_time --> allocated_time_total

allocated_time* are in the unit of fiberhour.

Any comments (especially column names) are welcome.