Handle package access visibility

[ryuukk]

If module a has functions that are marked package, they should be only seen when requesting completions from a module within package a

https://dlang.org/spec/attribute.html#package

Relevant region:

DCD/src/dcd/server/autocomplete/complete.d

Lines 755 to 767 in 57794ca

	bool mightBeRelevantInCompletionScope(const DSymbol* symbol, Scope* scope_)
	{
	import dparse.lexer : tok;
	if (symbol.protection == tok!"private" &&
	!scope_.hasSymbolRecursive(symbol))
	{
	// scope is the scope of the current file so if the symbol is not in there, it's not accessible
	return false;
	}
	return true;
	}