Add tests on limits format

[annanay25]

Signed-off-by: Annanay [email protected]

What this PR does:
#656 added new json struct tags to the limits config. This PR adds tests around it - parsing/matching.

@kavirajk - Can you review this please? Also, I hope the different formats in yaml/json don't affect our deployments. For instance, notice the ingestion_rate_limit_bytes field -

	inputYAML := `
ingestion_rate_strategy: global
ingestion_rate_limit_bytes: 100_000
`
	inputJSON := `{"ingestion_rate_strategy": "global", "ingestion_rate_limit_bytes": 100000}`

Which issue(s) this PR fixes:
Fixes na!

Checklist

• Tests updated
• NA Documentation added
• NA CHANGELOG.md updated - the order of entries should be [CHANGE], [FEATURE], [ENHANCEMENT], [BUGFIX]

[kavirajk]

LGTM! Thanks @annanay25 🎉