(fix) made boolean omitempty values references

[amaor-newrelic]

THIS IS A BREAKING CHANGE
This PR addresses a number of issues with the API used to update channels and destinations

1. It was impossible to update any boolean field from true to false
2. Empty filter was not marshalled correctly
   Unfortunately, it was impossible to implement these changes in a backward-compatible way. The current API is just does not match our GraphQL API.

See this pr for reference

[CLAassistant]

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1 out of 2 committers have signed the CLA.

✅ amaor-newrelic
❌ mbazhlekova
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[mbazhlekova]

@amaor-newrelic Thank you for your contribution! Sorry for the delay on this. We're doing some feature work that we're hoping to get into v2 before releasing another major version since it's a bit of a hassle in Go. Happy to review once that work is finished.