Warn about using `return` inside inline callback blocks [ci skip]

Closes #12981
Changelog improvements [ci skip]
Get rid of hack for freezing time on AR tests

We can now make use of the existent #travel/#travel_to helper methods
added to AS test case and available in all tests.
[ci skip] added after_touch callback documentation

[ci skip] added more explanation for `after_touch` callback
Merge pull request #13032 from kuldeepaggarwal/after_touch_documentation

[ci skip] added after_touch callback documentation [ci skip]
Variants inline syntax documentation [ci skip]

  * Extend method documentation
  * Mention it in actionpack/CHANGELOG
  * Update release notes
Spelling and Grammar checks
Moving the common code of increment and decrement of cache file store into seprate function

Removing the double checking for the value of id

simplifying code for checking conditional code for key

Removing the default values for parameters

removing reduntant code and asiigning value of id in local variable

removing wrongly added line break[ci ckip]

reverting code
Translate new unique constraint for sqlite >= 3.8.2
Merge pull request #13291 from strzibny/new_unique_constraint

Translate new unique constraint error message for sqlite >= 3.8.2
Merge pull request #13290 from strzalek/inline-syntax-docs

Variants inline syntax documentation
Merge pull request #13268 from aayushkhandelwal11/master

Moving the common code of increment and decrement of cache file store in...
Copy-edit the parent commit
Merge pull request #13271 from chancancode/warn_about_using_return_in_as_callbacks

Warn about using `return` inside inline callback blocks [ci skip]
Merge pull request #13293 from akshay-vishnoi/typo

Spelling and Grammar checks [ci skip]
PR #10635 introduces rescue from ArgumentError thrown by `Base64.strict_decode64`.

This broke natural order of things for `StaleSessionCheck#stale_session_check!` which tried auto_loading a class based on `ArgumentError` message , and later retrying the `Marshal#load` of class, successfully allowing auto_loading.

  This PR tries to fix this behavior by forwarding `ArgumentError` 's not raised  by `Base64.strict_decode64` , as is, ahead to `StaleSessionCheck#stale_session_check!`
Merge pull request #13229 from vipulnsward/fix-10635-tests

Fix test-error introduced by #10635.
make sure cached table name is a string. fixes #12582
remove the nil check from set_inverse_instance

methods that call set_inverse_instance with a record will not have to
pay the cost of a nil check on every call