feat(lib): Add DynamicListTerraformIterator with support for lists or sets with objects that have properties that are only known at apply time

[ansgarm]

Note! This PR is based on #3272

Problem

Terraform does not support iterating over lists without turning them into a set first. Sets that contain computed values need to be applied using -target in order for Terraform to know about these values before a plan is made. Using -target and applying changes in two passes is not desirable. However, there’s a workaround by turning them into maps which is described below.

Workaround by using Maps

A workaround for this case is to turn the set of objects into a map with keys that are based on arguments that are known during the plan stage. This is done for example in the HCL docs snippet for the aws_acm_certificate_validation resource:

In the snippet above, the set of objects stored in domain_validation_options is converted into a map with the domain_name of each object as the key.

If one instead tries to directly use domain_validation_options, the following error is printed (hinting at using -target, as described in the problem section above):

Solution

Allow the user to pass the attribute name to be used as the key in the map and convert the set/list into a map using a for expression.

Closes #2178
Related to #2001, #1393, #430 (some already closed with workarounds)

[DanielMSchmidt]

I like the approach overall and to my knowledge it looks good 👍 There are a few things missing for the overall picture from my point of view, let me know what you think:

• Documentation section about this (detailing the use-case & usage)
• Hcl2cdk needs to be made aware of this, ideally we would detect dynamic blocks / for_each being used from a complex list and then add the correct fromComplexList invocation. This will allow us to remove yet another escape hatch 🎉

[ansgarm]

Merging even though C# example fails on the pluckProperty call, which is a problem that's not directly related to this branch and something that @DanielMSchmidt is looking into.

[github-actions]

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