Simplify conditionals/DRY up the k3d dev script

Main change in this MR is an incremental build of the k3d cluster create command. This saves us from a mess of nested conditionals and handling every combination of options. It prevents a lot of repetition in the commands used and makes it easier to extend with other k3d options if needed.

Assuming I changed things properly this shouldn't change any behavior, just the under the hood code.

added kinddocs label

requested review from @kevin.wilder and @BrandenCobb

assigned to @micah.nagel

added statusreview label

changed the description

requested review from @brettcharrier

Main driver for this change - Brett was planning to add support for a -t option which would modify k3d to add the required mounts for Twistlock defenders.

The previous way of handling each option would double the amount of code we need each time we want to add a new option for k3d (you would have to add an if/else every spot that a k3d cluster create command is). By switching to an incrementally built command we can share the common k3d settings across all cases and add unique parameters with single conditionals without having to worry about combinations of conditionals. This should extend fairly well unless we run into cases where multiple parameters affect the same k3d argument.

i will test and approve if it looks good.

at some point in the future would like to switch the k3d create to a yaml config file.
These changes will make that refactor easier.

approved this merge request

approved. LGTM

approved this merge request

merged

mentioned in commit 90dd3f9c