[WIP] Parse invalid numbers and throw an error

[brunokim]

Description

Add a rule to parse numbers with invalid placement of underscores, either trailing, consecutive,
or beside the decimal point. Throw an error if such a number is found.

Note: numbers with a leading underscore are also invalid, but depending on the context
they are valid identifiers, e.g., LIMIT _123 is invalid, but SELECT _123 is not. Detecting these
cases would require deeper changes to the grammar, which may not be warranted just to
produce a better error message.

Additional context and related issues

#24784

Release notes

(x) Release notes are required, with the following suggested text:

## General
* Improve error message for invalid numbers. ({24784}`24784`)

[kasiafi]

@brunokim I'm not sure if we want to replace one error message with the other.

The original issue discusses a case of evidently malformed numbers: 123__456.789.

However, like you noted, there are also other cases where the new error message will take over. One example is a column name starting with a number: SELECT 1_. In this case, we'd rather keep the old error message, which has a suggestion that the user should quote the column name: identifiers must not start with a digit; surround the identifier with double quotes.