Prevent invalid code when using dynamic finders with Ruby's reserved words.

The dynamic finder was creating the method signature with the parameters name,
which may have reserved words and this way creating invalid Ruby code.

Closes: #13261

    Example:

        # Before
        Dog.find_by_alias('dog name')

        # Was creating this method
        def self.find_by_alias(alias, options = {})

        # After
        Dog.find_by_alias('dog name')

        # Will create this method
        def self.find_by_alias(_alias, options = {})
typo rectified [skip ci]
Merge pull request #13270 from aayushkhandelwal11/typos

typo rectified
Remove require 'models/administrator', Administrator is not used in secure password test
Merge pull request #13273 from robertomiranda/test-remove-require

Remove require 'models/administrator', Administrator is not used in secure password test
removing multiple check conditions to single check condition
Merge pull request #13276 from aayushkhandelwal11/change_to_key

removing multiple check conditions to single check condition
Bring back the valid_options class accessor

It is need in activerecord-deprecated_finders
Revert "Merge pull request #12518 from vipulnsward/remove_count_options"

It is needed for activerecord-depecated_finders

This reverts commit dcff027a5242b20c0c90eb062dddb22ccf51aed9, reversing
changes made to 3a2093984ff49d86db1efeff0c7581e788ecfb9f.
Mark the arguments needed by activerecord-deprecated_finders with a TODO
Revert "Merge pull request #13276 from aayushkhandelwal11/change_to_key"

This will call primary_key two times

This reverts commit d0588a2e897d33c6c12e9fc5f8680328d37a26ca, reversing
changes made to 87e1e86640fb8b5a260ff7c0044aaae58fff2bc4.
Revert the whole refactoring in the association builder classes.

This is to get activerecord-deprecated_finders work again
Make ActionDispatch::Request::Session#fetch behave like Hash#fetch

Session#fetch was mutating the session when given a default argument
and/or a block. Since Session duck-types as a Hash, it should behave
like one in these cases.
Nodoc missing number helper classes in AS [ci skip]

These classes are not meant to be public.
Move the parameter normalization to the initialize method

activerecord-deprecated_finders expects the parameters denormalized in
its initialize method
Merge branch 'support-deprecated-finders'
value is "disabled" not "disable"
Merge pull request #13264 from laurocaetano/fix_dynamic_finder_with_reserved_words

Prevent invalid code when using dynamic finders with reserved ruby word.
Remove not necessary file, move constants to the file they are used

File 'empty_bool.rb' was introduced around 4 years ago in
c10958fbddb22052e7cbe5fe6b825cda3cb26e48 to remove method redefined
warning in AS test suite, however we do not have such need for reuse
anymore, so we can safely move the constants back to the file where
they are currently used and get rid of the extra file/require.
Merge pull request #13280 from waynn/patch-4

value is "disabled" not "disable"