refactor(agent): Format agent code

[agrski]

What this PR does / why we need it:
This PR improves the formatting of various parts of the Core v2 agent's codebase. Improvements includ:

• Adding blank for logical grouping (and easier navigation in some editors/modes).
• Splitting long lines, e.g. for method signatures, over multiple lines. This aids legibility, as humans are generally not good at reading across wide texts. Part of this is about too many things on one line, which makes separating them difficult, and another part of it is about how much eye movement is required to scan code.
• Using more consistent splitting of lines. Maintaining consistency sets expectations for how to read the code and minimises the risk of important information being (literally) overlooked.

This PR should be a pure refactor; no functional changes are expected to have been introduced.

Which issue(s) this PR fixes:
N/A

Special notes for your reviewer:
N/A