refactor: updates func IsIPInRange to handle IP range, CIDR, single IP

[manoj-nutanix]

What problem does this PR solve?:
Follow up PR of https://github.com/nutanix-cloud-native/cluster-api-runtime-extensions-nutanix/pull/1001/files#r1884249547

Which issue(s) this PR fixes:
Fixes https://jira.nutanix.com/browse/NCN-104787

How Has This Been Tested?:

Special notes for your reviewer:

[dlipovetsky]

I disagree with the suggestion in https://github.com/nutanix-cloud-native/cluster-api-runtime-extensions-nutanix/pull/1001/files#r1884249547. I believe we should not make this change. The function becomes more difficult to use, because it is no longer clear what a valid input is.

The comment mentions 3 use cases (IP in an IP range, IP in a CIDR, IP in IP range where the start and end IP are the same). I see no need to avoid multiple functions for each use case. Our API fields have (and should have) unambiguous types. We do not have any field that can be an IP, an IP range, or a CIDR. Therefore, validation functions can choose the correct function to call.

We can write a straightforward function to check an IP in a CIDR. (The comment also mentions a range of one IP; in that case, it's possible to make a /32 CIDR from the IP).

[manoj-nutanix]

I disagree with the suggestion in https://github.com/nutanix-cloud-native/cluster-api-runtime-extensions-nutanix/pull/1001/files#r1884249547. I believe we should not make this change. The function becomes more difficult to use, because it is no longer clear what a valid input is.

The comment mentions 3 use cases (IP in an IP range, IP in a CIDR, IP in IP range where the start and end IP are the same). I see no need to avoid multiple functions for each use case. Our API fields have (and should have) unambiguous types. We do not have any field that can be an IP, an IP range, or a CIDR. Therefore, validation functions can choose the correct function to call.

We can write a straightforward function to check an IP in a CIDR. (The comment also mentions a range of one IP; in that case, it's possible to make a /32 CIDR from the IP).

ik it's not idiomatic but I've seen suggestion to create such unnecessary wrapper funcs in past so created a separate PR otherwise it would have delayed original PR if we kept discussing the suggestion on original PR. It's okay skip this change if we have agreement.

[manoj-nutanix]

closing in favour of #1007 (comment) .. we can revisit if need be.