rename implicit_saturating_{add,sub} and inverted_saturating_sub

[ada4a]

As per #clippy > `implicit_saturating_{add,sub}`: rename to `manual_*`

changelog: [implicit_saturating_add]: rename to manual_saturating_add
changelog: [implicit_saturating_sub]: rename to manual_saturating_sub
changelog: [inverted_saturating_sub]: rename to almost_saturating_sub

[rustbot]

r? @blyxyas

rustbot has assigned @blyxyas.
They will have a look at your PR within the next two weeks and either review your PR or reassign to another reviewer.

Use r? to explicitly pick a reviewer

[github-actions]

Lintcheck changes for e2fb5e8

Lint	Added	Removed	Changed
clippy::implicit_saturating_sub	0	3	0
clippy::manual_saturating_sub	3	0	0

This comment will be updated if you push new changes

[rustbot]

This PR was rebased onto a different master commit. Here's a range-diff highlighting what actually changed.

Rebasing is a normal part of keeping PRs up to date, so no action is needed—this note is just to help reviewers.