terraform: access list support

[hugoShaka]

This PR adds access list support to the Terraform provider. Since we stopped using gogoproto, generating new resources became increasingly complex.

The access list terraform schema was generated from the protobuf types and not the ones in api/types, which causes all kinds of small oddities from a user PoV, and made this PR way more complex.

User-facing limitations:

• the metadata field is nested under the header one because of the protobuf structure
• the traits is not a map but a list of structs, each struct with a key and a value attribute

Non user-facing limitations the PR had to work around:

• the protobuf time is different from go's time, I initially wanted to create ProtoTimeType/ProtoTimeValue but we cannot embbed a protobuf timestamp directly (because it contains a lock, the terraform
  value must be a reference, which is not supported by the protoc generator). The workaround is to use custom types (Timestamp and Duration). Requires: Add custom_types config parameter protoc-gen-terraform#36
• the provider has to do the conversion between the proto type and the api/type. This required writing a new provider template for new non-gogo resources (gen/plural_data_source_new.go.tpl and gen/plural_resources_new.go.tpl)
• The time type difference caused conversion issues fixed by convert go's zero time into protobuf zero's time teleport#32135

[hugoShaka]

Note: linting and tests are all over the place because I changed the teleport and teleport/api references to origin/master. Once gravitational/teleport#32135 is merged and backported, I'll update the replace statements and things should be less red.

[mdwn]

Overall this LGTM. The new templates look reasonable, but it's a little tough for me to review the very Terraform specific generator code.

[marcoandredinis]

Looks good 👍

Did you test this on a local cluster?

[hugoShaka]

I hacked a bit, a breaking change in the plugin lib was pushed to branch/v14 and the plugins repo were not updated to deal with the break. I created a ref (hugo/aaaaaa) just before the breaking commit, until we fix the plugins we must not update the teleport and teleport/api versions.

The CI is also using a dev release of teleport as the tests require a change which was not in the latest release 14.0.0. This CI reference must be updated the next time we do an official v14 release.

[marcoandredinis]

a breaking change in the plugin lib was pushed to branch/v14 and the plugins repo were not updated to deal with the break

What change was it?

[hugoShaka]

What change was it?

gravitational/teleport@df6dc24#diff-ce5b43206a5487e9c590d632fb4893abd1e76577cdfdd5e01f1a25595216dc7cR47

[marcoandredinis]

@mdwn Can you please take another look?
I ended up removing the new generators and changing the old ones, so things change quite a bit but should still be the equivalent.