Add support for binlog_row_image NOBLOB

[altmannmarcelo]

Description

MySQL has the ability to reduce the size of the binlog transmitted between source and replica by sending a minimal row image. This helps to reduce the network bandwidth between servers.

Minimal/noblob row differs from full rows as follow:

   - INSERTS

      |-----------+--------------+-----------------------------------|
      | OPTION    | BEFORE IMAGE | AFTER IMAGE                       |
      |-----------+--------------+-----------------------------------|
      | 'minimal' | ---          | All columns where a value         |
      |           |              | was specified. Autoinc columns    |
      |           |              | are also set if not specified.    |
      |-----------+--------------+-----------------------------------|
      | 'noblob'  | ---          | All columns where a value         |
      |           |              | was specified, and all            |
      |           |              | non-blob columns. Autoinc columns |
      |           |              | are also set if not specified.    |
      |-----------+--------------+-----------------------------------|
      | 'full     | ---          | All columns                       |
      |-----------+--------------+-----------------------------------|

      - UPDATES

      |-----------+----------------------------+---------------------------|
      | OPTION    | BEFORE IMAGE               | AFTER IMAGE               |
      |-----------+----------------------------+---------------------------|
      | 'minimal' | PKE                        | All columns where a value |
      |           |                            | was specified             |
      |-----------+----------------------------+---------------------------|
      | 'noblob'  | PKE + all non-blob columns | All columns where a value |
      |           |                            | was specified, and all    |
      |           |                            | non-blob columns          |
      |-----------+----------------------------+---------------------------|
      | 'full     | All columns                | All columns               |
      |-----------+----------------------------+---------------------------|

      - DELETES
 
      |-----------+----------------------------+-------------|
      | OPTION    | BEFORE IMAGE               | AFTER IMAGE |
      |-----------+----------------------------+-------------|
      | 'minimal' | PKE                        | ---         |
      |-----------+----------------------------+-------------|
      | 'noblob'  | PKE + all non-blob columns | ---         |
      |           |                            |             |
      |           |                            |             |
      |-----------+----------------------------+-------------|
      | 'full'    | All columns                | ---         |
      |-----------+----------------------------+-------------|

https://dev.mysql.com/worklog/task/?id=5092

With noblob the before image will have the PK or UK + all non-blob fields. We need to either need the full row (which will not be send if the table has blobs) or identify the PKE (which will be mixed with all non-blob columns in the before row).

In order to support noblob we should have update and delete TableOperation that take into consideration that the key will contain the columns for the keys + some data. This new operations should accept that key.len() has more fields that the actual base table key. and using a mapping we should index the column position and its value (this information is available via TableMapEvent and BinlogRow) and extract the columns that are PK.

Change in user-visible behavior

Requires documentation change