Follow-up to #38463.
By isolating ARGV, we guard against commands inadvertently depending on
prior ARGV contents. Any such command will now behave consistently when
run via `Rails::Command.invoke`, whether coming from the Rails CLI or
from library code. Likewise, any ARGV mutations done by a command will
not affect code that executes after `Rails::Command.invoke`.
When secrets confirmed with the `secrets:edit` command, `secrets.yml.enc`
will change without updating the secrets.
Therefore, even if only want to check secrets, the difference will come
out. This is a little inconvenient.
In order to solve this problem, added the `secrets:show` command.
If just want to check secrets, no difference will occur use this command.
