Check spanners when assessing emptiness

Port of musescore#8430, part 2:
Previously, a staff's emptiness was calculated based on its note and annotation content. Since this is evaluated before the system was laid out, the system did not have pointers to its SpannerSegments. This commit adds a way to include whether a staff has any spanners
(particularly pedal markings and hanging slurs) in
assessing emptiness, creating more consistent/expected hiding behavior in HideMode::AUTO.

Plus port of musescore#8527:
This commit tweaks the changes from commit 54ebee4 (which checks for spanners when assessing staff emptiness) and ignores spanners that are "system" spanners (such as voltas or system text). This prevents a false-positive unhiding in the case of such system spanners.
Also, it prevents another false positive that occurred hen a spanner started on the first tick of the next system.

Plus fixing a regression with hairpins, resulting in the next system's staves to become unhidden

src/engraving/rendering/dev/systemlayout.cpp

@@ -590,6 +590,10 @@ void SystemLayout::hideEmptyStaves(System* system, LayoutContext& ctx, bool isFi
     staff_idx_t staffIdx = 0;
     bool systemIsEmpty = true;
 
+    Fraction stick = system->measures().front()->tick();
+    Fraction etick = system->measures().back()->endTick();
+    auto spanners = ctx.dom().spannerMap().findOverlapping(stick.ticks(), etick.ticks() - 1);
+
     for (const Staff* staff : ctx.dom().staves()) {
         SysStaff* ss  = system->staff(staffIdx);
 
@@ -601,6 +605,14 @@ void SystemLayout::hideEmptyStaves(System* system, LayoutContext& ctx, bool isFi
                 && !(isFirstSystem && ctx.conf().styleB(Sid::dontHideStavesInFirstSystem))
                 && hideMode != Staff::HideMode::NEVER)) {
             bool hideStaff = true;
+            for (auto spanner : spanners) {
+                if (spanner.value->staff() == staff
+                    && !spanner.value->systemFlag()
+                    && !spanner.value->isHairpin()) {
+                    hideStaff = false;
+                    break;
+                }
+            }
             for (MeasureBase* m : system->measures()) {
                 if (!m->isMeasure()) {
                     continue;

src/engraving/rendering/stable/systemlayout.cpp

@@ -589,6 +589,10 @@ void SystemLayout::hideEmptyStaves(System* system, LayoutContext& ctx, bool isFi
     staff_idx_t staffIdx = 0;
     bool systemIsEmpty = true;
 
+    Fraction stick = system->measures().front()->tick();
+    Fraction etick = system->measures().back()->endTick();
+    auto spanners = ctx.dom().spannerMap().findOverlapping(stick.ticks(), etick.ticks() - 1);
+
     for (const Staff* staff : ctx.dom().staves()) {
         SysStaff* ss  = system->staff(staffIdx);
 
@@ -600,6 +604,14 @@ void SystemLayout::hideEmptyStaves(System* system, LayoutContext& ctx, bool isFi
                 && !(isFirstSystem && ctx.conf().styleB(Sid::dontHideStavesInFirstSystem))
                 && hideMode != Staff::HideMode::NEVER)) {
             bool hideStaff = true;
+            for (auto spanner : spanners) {
+                if (spanner.value->staff() == staff
+                  && !spanner.value->systemFlag()
+                  && !spanner.value->isHairpin()) {
+                    hideStaff = false;
+                    break;
+                }
+            }
             for (MeasureBase* m : system->measures()) {
                 if (!m->isMeasure()) {
                     continue;