Cleanups:
- use non-format variants of Log/Print with no additional args;
- fold in Fprintf call with no args into the following one;
- add missing arg placeholder in format strings;
- use require.Positive instead of Greater(..., 0);
- rename function to fillWithZeros to avoid collision with builtin clear;
- define type for context key to avoid collisions.
* fixed new gocritic violations
* fixed new 'contextcheck' violations
* fixed 'gosec' warnings
* suppressed ireturn and varnamelen linters
* fixed tenv violations, enabled building robustness tests on arm64
* fixed remaining linux failures
* makefile: fixed 'lint-all' target when running on arm64
* linter: increase deadline
* disable nilnil linter - to be enabled in separate PR
