Push the specified character into the HTML entity decoder. The first character pushed MUST be the '&' character. Returns true if the character was accepted; otherwise, false.
Get the decoded entity value.
The decoded value, or the original pushed input when the entity is not valid.
Get the input characters pushed into the decoder.
The pushed input.
Reset the entity decoder.
An HTML entity decoder.
Port of MimeKit's HtmlEntityDecoder: push characters one at a time starting with '&', then read the decoded value.