Feat: Add external OCI cloud controller manager (#11378)

* Feat: add external OCI cloud controller manager template & variable

Signed-off-by: tico88612 <17496418+tico88612@users.noreply.github.com>

* Feat: add external OCI cloud controller manager workflow

Signed-off-by: tico88612 <17496418+tico88612@users.noreply.github.com>

* Feat: migrate external OCI CCM config check from OCI cloud provider

Signed-off-by: tico88612 <17496418+tico88612@users.noreply.github.com>

* cloud_controller: oracle: simpler asserts

Make the asserts check for Oracle Cloud Infrastructure external cloud
controller more compact, and hence readable.
Allows to put them back in the main tasks for less back and forth when
reading the code.

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Signed-off-by: tico88612 <17496418+tico88612@users.noreply.github.com>
Co-authored-by: Max Gautier <mg@max.gautier.name>