Support parsing of environment variables other than strings.

[robertjsullivan]

Currently the go-cfclient throws an error when attempting to retrieve env vars for an app that are not of type string.

For example, given the env vars:

○ → cf curl /v3/apps/a275abd1-8f53-4a63-b980-d81cee1cf133/environment_variables
{
   "var": {
      "SCS_CREDHUB_ENABLED": true,
      "JBP_CONFIG_OPEN_JDK_JRE": "{jre: {version: 17.+}}",
       ...
   },
   "links": {
      "self": {
         "href": "https://< sanitized >/v3/apps/a275abd1-8f53-4a63-b980-d81cee1cf133/environment_variables"
      },
      "app": {
         "href": "https://< sanitized >/v3/apps/a275abd1-8f53-4a63-b980-d81cee1cf133"
      }
   }
}

We observe the following failure:
time=2024-07-15T20:43:48.368890666Z caller=logger.go:73 level=error error="failed to get environment for app a275abd1-8f53-4a63-b980-d81cee1cf133: error decoding /v3/apps/a275abd1-8f53-4a63-b980-d81cee1cf133/env get response JSON before '': json: cannot unmarshal bool into Go struct field AppEnvironment.environment_variables of type string"

We added support for bool, float64 and int types. More could easily be added given our implementation but we weren't sure what other types could actually occur. Let us know if you have any questions or would like additional changes.

[linux-foundation-easycla]

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• ✅ login: robertjsullivan / name: Robert Sullivan (7cf4fa1)

[sneal]

LGTM, thanks for the PR!

From the CF API docs it's not exactly clear what can be returned in these env vars, but it does seem obvious from yourr example it's not always a string.