[lib/native] Remain consistent with url naming pattern

Summary:
Quick follow up for this comment. Though we no longer use parseKeysFromQRCodeURL, we have parseInstallReferrerFromInviteLinkURL. I decided to
match the convention with inviteLinkUrl and qrCodeLinkUrl, so I've renamed parseInstallReferrerFromInviteLinkURL to parseInstallReferrerFromInviteLinkUrl.

Test Plan: Ran flow and confirmed no errors

Reviewers: atul, ginsu

Reviewed By: ginsu

Subscribers: ashoat, tomek

Differential Revision: https://phab.comm.dev/D9112