Plugin fails when using overload interface

[LecrisUT]

Issue

When using overload inteface, e.g.

    interface my_func
        module procedure my_funca
        module procedure my_funcb
    end interface my_func

the plugin completely freaks out and cannot locate any other subroutine/interfaces, e.g. cannot jump to any other interface (although can jump to the the main overload interface)

Minimum working example

MWE

module my_mod
    implicit none
    private
    public :: my_func, my_funca, my_funcb, test
    interface my_func
        module procedure my_funca
        module procedure my_funcb
    end interface my_func
    interface
        module subroutine my_funca(a)
            integer, intent(in) :: a
        end subroutine my_funca
        module subroutine my_funcb(a)
            real, intent(in) :: a
        end subroutine my_funcb
        module subroutine test()
        end subroutine test
    end interface
contains
    module procedure my_funca
        print *, 'Debug message'
    end procedure my_funca
    module procedure my_funcb
        print *, 'Debug message'
    end procedure my_funcb
    module procedure test
        print *, 'Debug message'
    end procedure test
end module my_mod

program mwe_fortran_interface
    use my_mod
    implicit none

    integer a
    real b

    call my_funca(a)
    call my_funcb(b)
    call my_func(a)
    call my_func(b)
    call test()
end program

Here I cannot navigate to test, my_funca or my_funcb. What works is my_func though.

---

Related to: #66

[LecrisUT]

Well navigating this plugin's code is quite challenging. At least I've found a difference when I use interface my_func or not.

fortran-plugin/src/main/kotlin/org/jetbrains/fortran/ide/findUsages/FortranFindUsagesHandlerFactory.kt

Lines 20 to 23 in bf11abd

	is FortranEntityDecl ->
	FortranEntityDeclFindUsagesHandler(element, this)
	is FortranDataPath ->
	FortranDataPathFindUsagesHandler(element, this)

When it works correctly the element is detected as FortranEntityDecl, but with interface my_func it becomes FortranDataPath