EPA: Remove AddEpann commit 7

EPA: Remove [AddEpAnn] from HYPHEN in Parser.y

The return value is never used, as it is part of the backpack
configuration parsing.

EPA: Remove last [AddEpAnn] usages

Remove residual usage in GHC. It is still used
- In haddock TTG extension point definitions (to be removed)
- Some check-exact residual, to be removed
- Comments around DisambECP in PostProcess

EPA: Clean up [AddEpAnn] from check-exact

There is one left, to be cleaned up when we remove AddEpann itself

EPA: Remove [AddEpAnn] from haddock

The TTG extension points need a value, it is not critical what that
value is, in most cases.

EPA: Remove AddEpAnn from HsRuleAnn

EPA: Remove AddEpAnn from HsCmdArrApp
(cherry picked from commit dbc77ce8)