Pivot implementation and redesign (#69)

- Pivot support implementation 
- Rename queries into inquiries
- Rename editor into workspace
- Change result set format
- New JSON format for inquiries
- Redesign panels

src/components/IconButton.vue

@@ -0,0 +1,110 @@
+<template>
+  <div
+    :class="['icon-btn', { active }, { disabled }]"
+    @click="onClick"
+    @mouseenter="showTooltip($event, tooltipPosition)"
+    @mouseleave="hideTooltip"
+  >
+    <div class="icon"><slot /></div>
+    <div v-show="loading" class="icon-in-progress">
+      <loading-indicator />
+    </div>
+    <span v-if="tooltip" class="icon-tooltip" :style="tooltipStyle" ref="tooltip">
+      {{ tooltip }}
+    </span>
+  </div>
+</template>
+
+<script>
+import tooltipMixin from '@/tooltipMixin'
+import LoadingIndicator from '@/components/LoadingIndicator'
+
+export default {
+  name: 'SideBarButton',
+  props: ['active', 'disabled', 'tooltip', 'tooltipPosition', 'loading'],
+  components: { LoadingIndicator },
+  mixins: [tooltipMixin],
+  methods: {
+    onClick () {
+      this.hideTooltip()
+      this.$emit('click')
+    }
+  }
+}
+</script>
+
+<style scoped>
+.icon-btn {
+  box-sizing: border-box;
+  width: 26px;
+  height: 26px;
+  cursor: pointer;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  position: relative;
+}
+.icon-btn:hover {
+  border: 1px solid var(--color-border);
+  border-radius: var(--border-radius-medium-2);
+}
+
+.icon-btn:hover .icon >>> path,
+.icon-btn.active .icon >>> path,
+.icon-btn:hover .icon >>> circle,
+.icon-btn.active .icon >>> circle {
+  fill: var(--color-accent);
+}
+
+.disabled.icon-btn  .icon >>> path,
+.disabled.icon-btn  .icon >>> circle {
+  fill: var(--color-border);
+}
+
+.disabled.icon-btn {
+  cursor: default;
+  pointer-events: none;
+}
+
+.disabled.icon-btn:hover .icon >>> path {
+  fill: var(--color-border);
+}
+
+.icon-in-progress {
+  position: absolute;
+  width: 26px;
+  height: 26px;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  background-color: var(--color-bg-light);
+  will-change: opacity;
+  /*
+    We need to show loader in 1 sec after starting query execution. We can't do that with
+    setTimeout because the main thread can be busy by getting a result set from the web worker.
+    But we can use CSS animation for opacity. Opacity triggers changes only in the Composite Layer
+    stage in rendering waterfall. Hence it can be processed only with Compositor Thread while
+    the Main Thread processes a result set.
+    https://www.viget.com/articles/animation-performance-101-browser-under-the-hood/
+  */
+  animation: show-loader 1s linear 0s 1;
+}
+
+@keyframes show-loader {
+  0% {
+    opacity: 0;
+  }
+  99% {
+    opacity: 0;
+  }
+  100% {
+    opacity: 1;
+  }
+}
+
+.icon {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+}
+</style>