Famous Catholic saints are often surrounded by various popular beliefs. Or sometime there is little that is actually known about the life of a saint (e.g. we don't seem to know that much about Thomas Aquinas). Is there an official website where the Vatican provides the official canonization documents of saints (old or recent)?
Where can we find the official records of canonizations?
If one were to look with some difficulty and in very specific Catholic libraries, such as some traditional monastic or seminaries, you may be able to find a copy in the reference section the source you are looking for.
The following book published by the Vatican (Congregatio pro Causis Sanctorum) every so many years has the information you desire:
The status of every single person proposed for sainthood is in there. When cults of saints are suppressed, it will state why. Every canonization and beatification is alphabetically listed. It is however only in Latin and is hard to find.
The Holy See is not a fan of putting all their richness of information online. Thus many researchers must make use of the now slower method: books and other documents!
The Acta Sanctorum is a collection of official saints' lives by various authors used for their processes of beatification or canonization.
The Acta Sanctorum Database is an online, subscriber-only edition.