Add resource for chart and dashboard

[AdityaHegde]

This adds basic resources for chart and dashboard. We are using vega lite config definition for charts. Dashboard will contain a list of charts. Examples,

kind: chart
title: My chart

# Data query
data:
  name: MetricsViewAggregation
  args:
    metrics_view: foo
    dimensions:
      - name: __time
        time_grain: year
    measures:
      - total_sales
    where:
      cond:
        op: GTE
        args:
	        - identifier: bar
	        - value: 'Something'
vega_lite: > 
{
  "$schema": "https://vega.github.io/schema/vega-lite/v5.json",
  "description": "A simple bar chart with embedded data.",
  "mark": "bar",
  "encoding": {
    "x": {"field": "time", "type": "nominal", "axis": {"labelAngle": 0}},
    "y": {"field": "total_sales", "type": "quantitative"}
  }
}

# dashboards/my_dashboard.yaml
kind: dashboard
title: My dashboard

# Define grid units
grid:
  columns: 12
  rows: 20

# Define components in the grid
components:    
  - chart: my_chart
    columns: 3
    rows: 5
  - chart: chart_2

[begelundmuller]

I think Vega calls them "specifications" instead of "configurations", so maybe vega_lite_spec?

[begelundmuller]

Doesn't seem like these need two null value types – because there's no visual meaning to setting them to 0. So would consider skipping optional and using 0 to indicate "infer".

[AdityaHegde]

Hmm not sure if this will work if we want to differentiate between (0,0) and not specified. Honestly lets keep this as is for now. Once we have a prototype from UI side we can tweak this.

[AdityaHegde]

But lets keep this not optional for now. That makes the most sense and we can change to optional if needed.

[begelundmuller]

More a discussion than a change request, but – not sure I see the point in a configurable grid, especially not for rows. For rows, wouldn't the size just always depend on the number of components? For columns, it feels like you would want the number to be dynamic depending on the screen width (with each column corresponding to a certain number of pixels, for example).

[AdityaHegde]

I saw this more like total width and height. Take this for example,

<!-- columns=6 rows=5 -->
<div class="grid grid-cols-6 grid-rows-5>
  <!-- chart-1 columns=2 rows=3 -->
  <div class="col-span-2 row-span-3">
  ...
  </div> 
</div>

This is still up in the air TBH. We will probably change this quite a lot once the prototype is done.

[mindspank]

Depends on how we want to layout components but a component will/should be able to occupy varying col and row spans. Imagine a 12x12 grid and you have 1 component occupying 2 columns and 12 rows and then 2 components occupying 10 cols and 6 rows each.

[begelundmuller]

nit: lowercase Data

[AdityaHegde]

Was getting a module not found error while running make proto.generate without this.