Adds the lasers to the multisystem framework

Description

Adds the lasers to the multisystem framework.

The lasers are now parsed as external partners and can support the Lorentz force. The parsing is splitted such that this is compatible with generic systems.

A test is added for the Lorentz force with a charged particle.

News snippet

Adds the lasers to the multisystem framework

Checklist

• I have checked that my code follows the Octopus coding standards
• I have added tests for all the new features added in this request.

src/hamiltonian/lasers.F90

@@ -141,7 +141,7 @@ contains
     character(len=200) :: envelope_expression, phase_expression
     FLOAT :: omega0, rr, pot_re, pot_im, xx(3)
 
-    PUSH_SUB(lasers_parse)
+    PUSH_SUB(lasers_parse_stage1)
 
     call messages_obsolete_variable(this%namespace, "TDLasers", "TDExternalFields")
     !%Variable TDExternalFields
@@ -540,7 +540,7 @@ contains
   subroutine lasers_copy_quantities_to_interaction(partner, interaction)
     class(lasers_t),      intent(inout) :: partner
     class(interaction_t), intent(inout) :: interaction
-      
+
     integer :: il, ip
     FLOAT :: field(3)
 
@@ -557,7 +557,7 @@ contains
       ! Looping over the lasers
       do il = 1, partner%no_lasers
         field = M_ZERO
-        select case(laser_kind(partner%lasers(il))) 
+        select case(laser_kind(partner%lasers(il)))
         case(E_FIELD_ELECTRIC, E_FIELD_VECTOR_POTENTIAL)
           call laser_electric_field(partner%lasers(il), field, partner%clock%time(), CNST(0.001))
           do ip = 1, interaction%system_np
@@ -567,8 +567,8 @@ contains
           call laser_field(partner%lasers(il), field, partner%clock%time())
           do ip = 1, interaction%system_np
             interaction%partner_B_field(:, ip) = interaction%partner_B_field(:, ip) + field(:)
-          end do      
-        case (E_FIELD_SCALAR_POTENTIAL) 
+          end do
+        case (E_FIELD_SCALAR_POTENTIAL)
           call messages_not_implemented("Lorentz force with laser scalar potential", namespace=partner%namespace)
         end select
       end do
@@ -1031,7 +1031,7 @@ contains
     integer :: il
 
     PUSH_SUB(load_lasers)
-   
+
     lasers => lasers_t(namespace)
 
     call lasers_parse_stage1(lasers)