chore: Remove more namespace imports

[aapoalas]

Removed more namespace imports, mostly trivial matters of no particular interest. (#1894 )

Two points of interest did appear, however:

1. gimletlet/app-mgmt.toml is failing from exceeding the task stack size. I assume this is not important since CI is not failing, but I fixed it nonetheless.
2. lpc55pins build auto-generates some imports, and in one case the generated import duplicates an existing import for the Direction enum. I avoided this by not importing it in the generated code and using the fully qualified name for that enum instead.