Remove data source template_file and move to the templatefile function

[fsadykov]

Hello @fuchicorp/contributors,

Please remove the template_file data source from the helm chart terraform module. We need to make sure that terraform module will work on mac or windows

I got the following error on the mac

Initializing provider plugins...
- Finding latest version of hashicorp/kubernetes...
- Finding hashicorp/helm versions matching "2.5.1"...
- Finding hashicorp/local versions matching "2.2.3"...
- Finding hashicorp/template versions matching "2.2.0"...
- Installing hashicorp/kubernetes v2.18.1...
- Installed hashicorp/kubernetes v2.18.1 (signed by HashiCorp)
- Installing hashicorp/helm v2.5.1...
- Installed hashicorp/helm v2.5.1 (signed by HashiCorp)
- Installing hashicorp/local v2.2.3...
- Installed hashicorp/local v2.2.3 (signed by HashiCorp)
╷
│ Error: Incompatible provider version
│ 
│ Provider registry.terraform.io/hashicorp/template v2.2.0 does not have a package available for your current platform, darwin_arm64.
│ 
│ Provider releases are separate from Terraform CLI releases, so not all providers are available for all platforms. Other versions of this provider may have different platforms
│ supported.

[mirlanimash]

WIKI