fix: upgrade hcloud-go to v2

[jooola]

Attempt to migrate the hcloud-go library to v2, to be able to finally drop the v1 version.

We previously discussed of not going this route, but the effort of porting new features in both hcloud-go versions is bigger than upgrade the library in the terrafrom plugin.

If this change ends up being impossible to test and too dangerous, we will just continue the route we initially choose: migrating for to the plugin framework then the hcloud-go library.

Related to #877

[codecov]

Codecov Report

Attention: Patch coverage is 89.06883% with 27 lines in your changes missing coverage. Please review.

Project coverage is 66.43%. Comparing base (b8df16a) to head (c5a02ae).

Files with missing lines	Patch %	Lines
internal/util/sdk.go	47.05%	8 Missing and 1 partial ⚠️
internal/util/id.go	63.63%	7 Missing and 1 partial ⚠️
hcloud/plugin_provider.go	0.00%	2 Missing ⚠️
internal/loadbalancer/resource_target.go	81.81%	2 Missing ⚠️
internal/primaryip/resource.go	84.61%	2 Missing ⚠️
hcloud/provider.go	50.00%	1 Missing ⚠️
internal/firewall/resource.go	83.33%	1 Missing ⚠️
internal/floatingip/resource.go	85.71%	1 Missing ⚠️
internal/network/resource_subnet.go	75.00%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##             main    #1062       +/-   ##
===========================================
+ Coverage   30.57%   66.43%   +35.85%     
===========================================
  Files          67       69        +2     
  Lines        9951     9924       -27     
===========================================
+ Hits         3043     6593     +3550     
+ Misses       6868     2617     -4251     
- Partials       40      714      +674     

Flag	Coverage Δ
e2e	66.43% <89.06%> (?)
unit	30.86% <10.93%> (+0.28%)	⬆️

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[apricote]

Looking through it I am hopeful for the future of hcloud-go!

I am a bit worried about the naked int() castings to downcast for terraform on 32 bit platforms. Go just does it, resulting in bad data. What do you think about adding a reverse function that converts from int64 to int on 64-bit platforms, and errors on 32-bit platforms?

[jooola]

I am a bit worried about the naked int() castings to downcast for terraform on 32 bit platforms. Go just does it, resulting in bad data. What do you think about adding a reverse function that converts from int64 to int on 64-bit platforms, and errors on 32-bit platforms?

Yup, that's a sensible idea. I addressed your review comments and implement this for the relevant casts.