analytic_fields_view_get: fixed an issue when using the oe_analytic div for tree views. Fields are now generated with an empty JSON dict as their default 'modifiers' attribute.

Bound dimensions: if an analytic code ID is passed to create or write, it will be ignored unless the key "force_code_id" is set to True in the context.

Add some help

- "Structure" -> "Structures"

extract_values can be used to copy analytic (or para-analytic) data from an object to another.
format_field_name returns an analytic field's name from its slot, prefix and suffix.

Fixed a bug that could break views when using the oe_analytic div without any analytic field to place.