Implement a high-level API for ES|QL AST mutations.

• Ability to add/remove METADATA fields
• Ability to add/remove WHERE commands
• Ability to change LIMIT
• Ability to add/remove SORT command expressions
• Ability to add/remove FROM sources

The API

The API could look something like below.

Manipulate METADATA fields:

// Remove METADATA field
Query.removeFromMetadata('_id');
// Add METADATA field
Query.addFromMetadata('_id');

Remove commands:

Query.removeCommands(node => node.name === 'limit');
// or
Query.removeCommandsByName('limit')

Change LIMIT of the query:

// Change LIMIT to specific value
Query.limit.set(10);
// Remove LIMIT command
Query.limit.remove();

...