feat(sanitize): refactor (#4479)

lib/platform/azure/index.ts

lib/platform/bitbucket-server/index.ts

lib/platform/bitbucket/index.ts

lib/platform/github/index.ts

lib/platform/gitlab/index.ts

lib/util/host-rules.ts

lib/util/sanitize.ts

test/platform/azure/index.spec.ts

test/platform/bitbucket-server/index.spec.ts

test/platform/bitbucket/index.spec.ts

test/platform/github/index.spec.ts

test/platform/gitlab/index.spec.ts

test/util/__snapshots__/host-rules.spec.ts.snap

test/util/__snapshots__/sanitize.spec.ts.snap

test/util/host-rules.spec.ts

test/util/sanitize.spec.ts