C2INAV13 — Enumeration value ESTIMATED used twice in the same package

Using the value ESTIMATED in accuracy_derivation_type and navigation_derivation_kind_type causes problems when mapped to some programming languages; it is also better practice to be more descriptive.

Modify enumeration values to be more descriptive

Change the ESTIMATED enumeration values as follows:

In accuracy_derivation_type change to ESTIMATED_ACCURACY
In navigation_derivation_kind_type change to ESTIMATED_NAV_INFO