Widgets Improvements

[offtherailz]

Description

Improve current widgets system with some new features.

Please indicate if this issue is related to a bug or a new feature request

• Bug
• New Feature

Acceptance Criteria - AC

• requires Widgets: Implement counter widget  #2642. Possibility to display simple number indicator (without a chart) for max, min, average, sum, stddev.
• requires Widgets: improve widgets layout on map #2659. Improve widgets layout on map
• requires Widgets: Improve legend presentation for pie chart #2650. Improve legend presentation for pie chart.
• requires Widgets: customize query messages for query panel #2653. Query form messages should be customized for the current usage (now it shows search, Advanced Search ... but it should be have "Configure the filter" as title and "Save" instead of "Search" for the primary action button.
• requires Widgets: allow full screen #2667. Allow full screen.
• requires Widgets: Rethink gaudge chart #2652. Rethink gauge chart (TODO specify) and colors (for better reading)
• requires Implement table widget #2623. Tabular view of data (with virtual scrolling)
• requires Widgets: Advanced chart options #2654. Advanced chart options (feedback from C040):
• requires Widgets: minor changes to evaluate #2655. Minor changes to widgets and charts to evaluate (feedback from C040):
• requires Widgets: Indicate percentage on pie charts #2651. indicate percentage on pie charts
• GEOT-5844 - GEOT-5890 Null values in aggregate process rises an exception on GeoServer
• requires Widgets: Improve color ranges and selector #2656. Improve available colors and color ranges.
• requires Widgets: Multi variable charts and counter #2657. Multivariable charts.
• requires Widgets: Export legend in image #2658. Export legend in image.
• requires Make Group By and Operation optionals #2684. Make Group By and Operation optionals
• requires Remove Gauge widget for the time being #2675 --> Remove Gauge widget for the time being
• requires Implement STD for the Counter Widget #2676 --> Implement STD for the Counter Widget
• requires Improve Text Alignment for Counter #2677 --> Improve Text Alignment for Counter
• requires Improve Text Widget L&F #2678 --> Improve Text Widget L&F
• requires Label Change in Pie Chart #2681 --> Label Change in Pie Chart
• requires Counter Widget should have configurable text options #2687 -->Counter Widget should have configurable text options
• requires ColorRamp not selected when editing existing chart #2680 -->ColorRamp not selected when editing existing chart
• requires Allow people to start building a chart from the FeatureGrid #2682 -->Allow people to start building a chart from the FeatureGrid
• requires Make # of rows configurable #2690
• requires Make Group By and Operation optionals #2684 -->Make # of rows configurable -->Make # of rows configurable
• requires Make Group By and Operation optionals #2684 -->Introduce possibility to view data and potentially query
• requires Introduce ordering on column for table widget #2691 -->Introduce ordering on column for table widget