schema.Engine: need to improve on tables-with-sizes query

[shlomi-noach]

In #17066 we made substantial performance improvements to TablesWithSize80. During that work, we noticed the query does not cover all data.

As a reminder, this query is used to determine the total file size and allocated size (as reported by InnoDB) for all InnoDB tables. We focus on MySQL 8.0 here as there are other implementations for different versions.

What we noticed is we do not account for FULLTEXT indexes. These are not BTREEs; a FULLTEXT index is implemented by hidden InnoDB tables. Our query does not measure the file/allocated size for those tables.

Getting to read those sizes complicates the query even more, as it requires the introduction of information_schema.innodb_tables which helps us decipher which hidden InnoDB table belongs to which FULLTEXT-enabled table.

The objective is to read those table dimensions, while still maintaining good performance, in the same scale as that we achieved in #17066.