[Golang] Move utility functions from client.mustache to utils.mustache

[martinlakov]

Move the newStrictDecoder & reportError utility functions from client.mustache to utils.mustache

@antihax @grokify @kemokemo @jirikuncar @ph4r5h4d @lwj5

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[wing328]

thanks for the PR

please follow step 3 to update the samples

[martinlakov]

@wing328 @antihax @grokify @kemokemo @jirikuncar @ph4r5h4d @lwj5 - Samples have been re-generated accordingly

[wing328]

thanks for the PR. is it correct to say that this PR is a breaking change (without fallback)?

[martinlakov]

thanks for the PR. is it correct to say that this PR is a breaking change (without fallback)?

Shouldn't be - it is only moving two utility functions to utils.go. No new additions, no deletions.

This is important when only generating models and no controllers

[wing328]

thanks for the explanation. sounds reasonable for the use cases only generating model files.

closed via #19001 with updated samples.