Make Lint/RedundantSafeNavigation aware of several methods

[koic]

This PR makes Lint/RedundantSafeNavigation aware of blank?, presence, and present? methods.

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Before submitting the PR make sure the following are checked:

• The PR relates to only one subject with a clear title and description in grammatically correct, complete sentences.
• Wrote good commit messages.
• Commit message starts with [Fix #issue-number] (if the related issue exists).
• Feature branch is up-to-date with master (if not - rebase it).
• Squashed related commits together.
• Added tests.
• Ran bundle exec rake default. It executes all tests and runs RuboCop on its own code.
• Added an entry (file) to the changelog folder named {change_type}_{change_description}.md if the new code introduces user-observable changes. See changelog entry format for details.
• If this is a new cop, consider making a corresponding update to the Rails Style Guide.

[koic]

ee3554b fixes the following false positive for Lint/RedundantSafeNavigation when using blank?:

nil.presence || 42  # => 42
nil&.presence || 42 # => 42

nil.present? || 42  # => 42
nil&.present? || 42 # => 42

nil.blank? || 42    # => true
nil&.blank? || 42   # => 42