[Feature] - Get Region, OS and Plan by Name

[dirien]

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I am really upsad by the fact, that you are not offering a way to find a Region, OS or Plan by name. The only function is List.

Describe the solution you'd like
Extend the API to support filter by name. Same goes for the vultrgo sdk the ListOption

Describe alternatives you've considered
Right now, i have to iterate through the list of regions/plans/os to verify that the user input exist.

Additional context
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