This PR is dropping the column `targetColumnMap` of fieldMetadata
entities.
The goal of this column was to properly map field to their respecting
column in the table.
We decide to drop it and instead compute the column name on the fly when
we need it, as it's more easier to support.
Some parts of the code has been refactored to try making implementation
of composite type more easier to understand and maintain.
Fix#3760
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Co-authored-by: Charles Bochet <charles@twenty.com>
