Purpose
=======
Do not modify the cache in order to improve the performance when we
read in batch. Instead we create a new batched method "convert_to_read"
that check existence in batch, and generate a dict with the result.
Now, all the properties field checks (many2one existence, selection option
still exists, tag value stiff exist, etc) and done in "convert_to_read".
It means that doing `record.properties` won't do all those checks.
Having the batched field fetch at the convert_to_record required too
many changes for the scope of this task, so "record.properties" having
the cache values unchecked is an acceptable tradeoff currently, hence
we batch convert_to_read.
Task-2980121
Part-of: odoo/odoo#101901
std-odoo
da48700b59