Improve handing of executable comments in mariadb-dump and mariadb console

When using mariadb-dump a database, the dump always contains executable comments for things such as character sets and collations. In the same way the mariadb console always retains these comments. When going from one version to another or for other prurposes you would want to export and import schema or data although this is primarily focused for schema objects, then there is no way to export tables, procedures etc without including the character set / collation, so even if you want to change any of these when importing data, this just isn't possible. This could for example be an issue when moving from 10.6 to 11.8, import / export cannot be used to change the character set / collation of a schema object.
Some proposed ways to fix this is then:

• Add an option to mariadb-dump to not include the character set / collation to the output.
• Add an option to mariadb-dump to assume a given version for executable comments.
• Add an option to the mariadb console to ignore executable comments.
• Add an option to the mariadb console to assume a given version for executable comments
• Add a MariaDB Server system variable to disable executable comments or to set a specific version for them