fix: fixing issues reported in 2.18.0 release

[bejjrajesh]

Proposed changes

The following changes are made to the install script in support of the NIM 2.19.0 release.

1. The Security Module is no longer a separate module from NIM. It will be part of the NIM from 2.19.0. The -s option is updated to give a warning saying SM comes by default and not needed to be installed separately.
2. New option -f is added to support setting the FQDN name to be used for generating the certs for NIM.
3. Fixed the bug if the mgmt block is already present, do not add new block again.
4. Added new option -l that prints the list of supported distributions where script can be executed.

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Closes #ISSUE

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[github-actions]

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[mjang]

Recommending changes

[mjang]

recheck

[bejjrajesh]

I have hereby read the F5 CLA and agree to its terms

[bejjrajesh]

recheck

[mjang]

@travisamartin IMO this is ready. If you agree, you're welcome to merge.

[mjang]

@bejjrajesh Your most recent commit w/r/t curl makes sense to me.

[mjang]

Merging with validation from internal QA.