perf: nodata处理、npmLine.vue代码优化

src/assets/css/components/views/charts2/networkOverviewLine.scss

@@ -1,10 +1,11 @@
 .line.network {
   height: 100%;
   width: 100%;
+  position: relative;
   border: 1px solid #E2E5EC;
   border-radius: 4px;
   .chart-drawing {
-    height: 100%;
+    height: calc(100% - 74px);
     width: 100%;
     .echarts-tooltip.echarts-tooltip-dark {
       .cn-chart-body {

src/assets/css/components/views/charts2/networkOverviewPerformanceEvent.scss

@@ -27,6 +27,7 @@
       background: #E2E5EC;
     }
     .performance-event-pie {
+      position: relative;
       height: 50%;
       width: 100%;
       .chart-drawing {

src/assets/css/components/views/charts2/npmAppCategoryScore.scss

@@ -4,6 +4,7 @@
   width: 100%;
   display: flex;
   .npm-app-left {
+    position: relative;
     height: 100%;
     display: flex;
     flex: 1;

src/assets/css/components/views/charts2/npmEventsByType.scss

@@ -1,4 +1,5 @@
 .npm-event {
+  position: relative;
   width: 100%;
   height: 100%;
   .npm-event-title {

src/assets/css/components/views/charts2/npmLine.scss

@@ -1,4 +1,5 @@
 .npm-line {
+  position: relative;
   height: 100%;
   width: 100%;
   border: 1px solid #f0f0f0;