feat: sanitize VM names for OpenStack resource naming

[miguelntt]

Summary

VM names in VMware environments often contain accented characters,
special symbols or other characters that are not valid in OpenStack
resource names. This was causing failures or unexpected names in
Cinder volumes, Nova instances and Neutron ports.

Changes

plugins/module_utils/utils.go

Extended SafeVmName with three additional sanitization steps:

• Transliteration: common non-ASCII characters are mapped to their
  ASCII equivalent before the regex runs (e.g. ñ→n, ß→ss, ç→c,
  á→a). Covers Spanish, Portuguese, French, German and extended Latin.
• Underscore collapsing: consecutive underscores produced by the
  replacement step are collapsed into one (e.g. vm--01 → vm_01).
• Length limit: result is truncated to 64 characters and any
  trailing underscore left after truncation is stripped.

plugins/modules/src/migrate/migrate.go

SafeVmName is now applied to vmName when looking up an existing
volume and when setting the name of a newly created volume.

plugins/modules/src/create_server/create_server.go

SafeVmName is now applied to moduleArgs.Name in both code paths
that create a Nova instance.

plugins/modules/src/create_network_port/create_network_port.go

SafeVmName is now applied to moduleArgs.VmName when constructing
the Neutron port name.

tests/unit/utils_test.go

Updated existing test expectations to match the new behaviour and added
test cases covering underscore collapsing, transliteration (accented
vowels, ñ, ß, ç), truncation to 64 characters and trailing-underscore
stripping after truncation.

Testing

go test -v ./tests/unit/...

[fdiazbra]

Thanks for this comprehensive PR! The SafeVmName enhancement is a real improvement for handling non-ASCII VM names. However, there are a couple of issues that need to be addressed before merging:

• Remove changes from another PR
• Verify transliteration tests

[fdiazbra]

It looks like this PR includes changes from another PR

Could you please rebase this branch on the current main branch to include only the SafeVmName changes? This will make the review cleaner and avoid merge conflicts.

[miguelntt]

Thanks for the review! I've addressed both points:

1. Removed changes from another PR
Rebased the branch directly onto main, so the UpdateVolumeMetadata block from the skip-conversion fix no longer appears in this PR's diff.

2. Fixed transliteration tests
Replaced the test cases that were using plain ASCII strings with ones that actually exercise the non-ASCII characters being transliterated:

• Spanish: Ángel_García, Açaí_VM, Muñoz-Server, Ñoño_Server
• Portuguese/French: Château_prod, Hôtel_de_ville, São_Paulo
• German: Müller_vm, straße_01 (ß → ss)

[fdiazbra]

Looks good to me!