[Chores]: Provider Boost touch-ups

[shannonwells]

Description

Some suggested touch-ups we may consider or should do, from review comments. These can be separated into other issues but this will be the central one.

From @enddynayn:

• In pallets/capacity/src/lib.rs#on_initialize

Just leaving this as a note: we might want to consider using the new Poll hook instead of on_initialize. Here’s the relevant issue for reference: #2098.

• See if it's possible to do some refactors, especially for things like, increase_stake_and_issue_boost_capacity with increase_stake_and_issue_capacity. When I was implementing it, the code was getting really complicated and entangled so I separated it even though there would be some duplicate code. There could be other possibilities for small optimizations though.

• rename set_target_details to set_or_delete_target_details ?

• refactor to avoid upserting records. Split these up instead or just use the storage calls directly (inline), maybe.

• in start_new_reward_era_if_needed, @aramikm suggests to make the >= just an =.

• capacity_generated -> calculate_capacity: this was out of scope for the PR since this was its name before the feature.

Possible Related Issues

• [Chore]: Evaluate Moving on_initialize Functionality into New Hook Poll #2098

Searched for Related Issues

• I have done a search for related issues and either found none, or noted them