performance: expand contexts in parseInnerContexts

[jeswr]

Rather than

jsonld-context-parser.js/lib/ContextParser.ts

Lines 615 to 627 in 107a686

	if (this.validateContext) {
	try {
	const parentContext = {...context, [key]: {...context[key]}};
	delete parentContext[key]['@context'];
	await this.parse(value['@context'],
	{ ...options, external: false, parentContext, ignoreProtection: true, ignoreRemoteScopedContexts: true, ignoreScopedContexts: true });
	} catch (e) {
	throw new ErrorCoded(e.message, ERROR_CODES.INVALID_SCOPED_CONTEXT);
	}
	}
	context[key] = {...value, '@context': (await this.parse(value['@context'],
	{ ...options, external: false, minimalProcessing: true, ignoreRemoteScopedContexts: true, parentContext: context }))
	.getContextRaw()}

I propose that this section of code look more like the following (note the disabling of minimal processing):

context[key] = {...value, '@context': (await this.parse(value['@context'],
          { ...options, external: false, ignoreRemoteScopedContexts: true, parentContext: context }))
          .getContextRaw()}

This is because this takes the same time as the try/catch call and prevents the parser from needing to re-expand the context during parsing thus reducing repeated operations.

This will also remove the need for caching objects in the context caching work.

[rubensworks]

I'm pretty sure we need the old code, to enforce the ERROR_CODES.INVALID_SCOPED_CONTEXT error, which is required by the spec in specific cases (see spec tests in the jsonld-streaming-parser).
But if you find another way to throw this specific coded error, then it's fine by me :-)