ATLASRECTS-5781: First try for the first part. Cleaning up the strawCaches

ATLASRECTS-5781 (ATR-22378) : First try Not sure if works 100% (CI will prb tell us more)

The main changes:

- CxxUtils::CachedUniquePtrT<
      std::vector<std::unique_ptr<Trk::StraightLineSurface>>>
      m_strawSurfaces{};

-    CxxUtils::CachedUniquePtrT<std::vector<std::unique_ptr<SurfaceCache>>>
      m_strawSurfacesCache{};
+    std::vector<CxxUtils::CachedUniquePtr<Trk::StraightLineSurface>> m_strawSurfaces{};
+    std::vector<CxxUtils::CachedUniquePtr<SurfaceCache>> m_strawSurfacesCache{};

This means we can and do eagerly initialize the vectors since we can not the size during constuctions of an object. so these go

    TRT_BaseElement::createStrawSurfaces() const
    {
      auto strawSurfaces = std::make_unique<
        std::vector<std::unique_ptr<Trk::StraightLineSurface>>>(nStraws());
      m_strawSurfaces.set(std::move(strawSurfaces));
    }

    void
    TRT_BaseElement::createStrawSurfacesCache() const
    {
      auto strawSurfacesCache =
        std::make_unique<std::vector<std::unique_ptr<SurfaceCache>>>(nStraws());
      m_strawSurfacesCache.set(std::move(strawSurfacesCache));
    }

and we have

m_nstraws = m_descriptor->nStraws();
m_strawSurfaces.resize(m_nstraws);
m_strawSurfacesCache.resize(m_nstraws);

Due to discussion in !38322 (merged) and the JIRA we might want to be sure that the inner ptr are CachedUniquePtr

The above two combined give us

const Amg::Transform3D&
TRT_BaseElement::strawTransform(unsigned int straw) const
{
  if (!m_strawSurfacesCache[straw]) {
    Identifier id = m_idHelper->straw_id(identify(), straw);
    createSurfaceCache(id);
  }
  // forward the transform of the cache
  return *(m_strawSurfacesCache[straw]->transform());
}

instead of

const Amg::Transform3D& TRT_BaseElement::strawTransform(unsigned int straw) const
    {
      if (!m_strawSurfacesCache) {createStrawSurfacesCache();}
        SurfaceCache* sCachePtr = (*m_strawSurfacesCache)[straw].get();
        if (!sCachePtr) {
            Identifier id =  m_idHelper->straw_id(identify(), straw);
            createSurfaceCache(id);
            sCachePtr = (*m_strawSurfacesCache)[straw].get();
        }
        // forward the transform of the cache
        return *(sCachePtr->transform());
    }

    mutable std::vector<const Trk::Surface*> m_surfaces ATLAS_THREAD_SAFE; // Guarded by m_mutex
  mutable std::mutex m_mutex;

becomes

  //Cache of vector of non owning pointers for the straw surfaces  
    CxxUtils::CachedValue<std::vector<const Trk::Surface*>> m_surfaces;

I also used nullptr, default/delete, used a bit more unique_ptr Plus some other indentation aesthetic changes.

Mentiong @oda