make the NUKE_CERT variables case insensitive

[marionbarker]

Purpose:

Make the ENABLE_NUKE_CERTS and FORCE_NUKE_CERTS variables case insensitive.

• When entering a variable on my computer, it is natural to type true
• On my phone, the default is to begin whatever I type with a capital letter, causing True to be entered unless special care is taken

Several people have needed help to change their entries from True to true

This PR solves the issue.

Method

Convert the variables to lower case internally before using them.
In addition, I changed var.FORCE_NUKE_CERTS to be treated like ENABLE_NUKE_CERTS

Test

Test using dev branch and this PR to observe the effect of true, True and TRUE.
Realized during full testing that the FORCE_NUKE_CERT was already case insensitive with respect to whether nuking is forced

• not quite sure why that was happening
• I plan to come back later and repeat the testing

Upon closer inspection, the messages are handled in one bit of the code and the action is handled in a different bit of the code. This only modifies the part of the code with the messages in name: Set output and annotations based on Fastlane result in the create_certs job. It does not affect the code in nuke_certs job.

need cert?	ENABLE _NUKE_CERTS	FORCE _NUKE_CERTS	Status	Annotation
N	-	-	✅	🔔 Automated renewal of certificates is disabled because the repository variable ENABLE_NUKE_CERTS is not set to 'true'.
N	True	-	✅	with dev branch, get warning
N	True	-	✅	with this PR, no annotation
Y	True	-	❌	use dev branch, action fails
Y	True	-	✅	use this PR, get correct annotation: Nuke certificates ✅ But don't worry about your existing TestFlight builds, they will keep working! other expected messages
N	True	TRUE	✅	use dev branch - certs were forced - but no message about it
N	True	TRUE	✅	use this PR - ‼️ Nuking of certificates was forced because the repository variable FORCE_NUKE_CERTS is set to 'true'.
N	True	False	✅	use this PR - no nuking and no warning
Y	True	False	✅	use this PR - Nuke certificates] ✅ But don't worry about your existing TestFlight builds, they will keep working!