feat: Remove normalization of contexts

[rhcarvalho]

All of the context types documented in 1 are flat objects.

The more recent addition contexts.trace is the only context type that
may have nested objects under contexts.trace.data. That value holds the
data for the Transaction Span and matches spans[].data for invidual
Spans.

Removing normalization is one solution to the inconsistency in which
data in Transactions is heavily limited, while data in Span is ignored
by normalization.

This is the simplest to implement fix to #2646, thus what we implement
here to evaluate. We expect that no other key under contexts will be
affected negatively by this change.

Fixes #2646

[getsentry-bot]

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[rhcarvalho]

Talking to @bruno-garcia about a different subject, I learned that historically Event.contexts may have also been used (or might still be used today) to store arbitrary data, similar to Event.extra.

In that case, if this possibility is used in the wild in JS, we could have undesirable side effects.

I'd like to think this through in the light of the new learning.

---

normalizeDepth and the normalize function may indirectly shrink nested objects by converting potentially large object trees into a string like "[Object]", but it doesn't prevent people from replacing their deeply nested objects with long JSON strings by doing JSON.stringify(originalValue), which retains the large payload while making it less useful because of double JSON encoding.

sentry-javascript/packages/utils/src/object.ts

Lines 302 to 321 in fc53353

	/**
	* normalize()
	*
	* - Creates a copy to prevent original input mutation
	* - Skip non-enumerablers
	* - Calls `toJSON` if implemented
	* - Removes circular references
	* - Translates non-serializeable values (undefined/NaN/Functions) to serializable format
	* - Translates known global objects/Classes to a string representations
	* - Takes care of Error objects serialization
	* - Optionally limit depth of final output
	*/
	export function normalize(input: any, depth?: number): any {
	try {
	// tslint:disable-next-line:no-unsafe-any
	return JSON.parse(JSON.stringify(input, (key: string, value: any) => walk(key, value, depth)));
	} catch (_oO) {
	return '**non-serializable**';
	}
	}

---

And alternative I'd like to consider is to do normalize all of Event.contexts, but then overwrite Event.contexts.trace with the original non-normalized value. That seems to be the path of least harm.

[rhcarvalho]

The documentation for scope.setContext corroborates the idea that event.contexts is used as a bag of arbitrary data: https://docs.sentry.io/platforms/javascript/#extra-context

[rhcarvalho]

Given my last two comments, I'm closing this in favor of #2655.