[web] Proper usage of menus

See merge request ogs/ogs!3071

Extract compute shape functions for arbitrary points

See merge request ogs/ogs!3064

Fixes MR web preview links.

phase-field documentation

See merge request ogs/ogs!3069

This allows the function to be used independently of the
integration method.

The type is used as return type anyway, no advantage to
make the typedef private.

Exterior forces output in LiquidFlow and HeatConduction

See merge request ogs/ogs!3068

When compared to the surface flux the numbers for hydraulic flow
(aside from the boundary effects) are equal (scaled byth the
surface element area).

Both, Picard and Newton.

Fix compilation issues

See merge request ogs/ogs!3067

The error does not pop up when compiling a unity build.

gcc-8.3 complains otherwise about the comparison
operator being missing for two constant SegmentIterators.

[CI] Win python jobs

See merge request ogs/ogs!3066

A warning fix in NormalTractionBoundaryConditionLocalAssembler

See merge request ogs/ogs!3024

Refactor init shape matrices

See merge request ogs/ogs!3063

Can be used then in other places where not all of the
shape matrices are needed. Default to ALL, s.t. there
is no change to the code.

Putting IntegrationMethod after GlobalDim enables automatic
template argument deduction for that type.

Allow curve usage in function parameters

See merge request ogs/ogs!3058

Use MPL properties in HeatConduction process

See merge request ogs/ogs!3062

Use a Function type parameter with reference to the curve.

Allows usage of curves in Function type parameters.

Avoid instantiation of the NormalTractionBoundaryCondition
for the bulk mesh dimension one.

This allows the function to be called from outside,
given the GlobalDim template parameter is known.