Add string representation for rio accessor

[remi-braun]

Adding a quick string representation for the rio accessor.

Example for /app/test/test_data/input/veris.nc

rioxarray accessor (.rio) | RasterDataset
Variables:
        Name: 'Slope'
        'Slope' attributes:
                count: 1
                crs: 4326
                rasterio_dtype: float64
                nodata: -9999.0
                transform: | 0.00, 0.00,-94.30|
| 0.00,-0.00, 42.35|
| 0.00, 0.00, 1.00|
                height: 50
                width: 35
                blockxsize: 35
                blockysize: 1
                bounds: (-94.30306000000002, 42.350229999999996, -94.30271000000002, 42.350730000000006)
        Name: 'Red'
        'Red' attributes:
                count: 1
                crs: 4326
                rasterio_dtype: float64
                nodata: -9999.0
                transform: | 0.00, 0.00,-94.30|
| 0.00,-0.00, 42.35|
| 0.00, 0.00, 1.00|
                height: 50
                width: 35
                blockxsize: 35
                blockysize: 1
                bounds: (-94.30306000000002, 42.350229999999996, -94.30271000000002, 42.350730000000006)

[remi-braun]

This helps to quickly grasp the dataset information, a bit like printing ds.meta in rasterio

[snowman2]

I like the idea of having a string representation. However, I would like to think about how this could look like before moving forward. May be worth opening an issue to discuss.

[remi-braun]

Ok I'll open one :)

[remi-braun]

I added the suggestions you added in #917

Now the DataArrays look like:

    rioxarray.RasterDataArray: (y[latitude (m)]: 10, x[latitude (m)]: 10, z[band]: 1)
    Profile:
        count: 1
        crs: 32605
        dtype: float32
        nodata: 0.0
        transform:
            | 10.00, 0.00, 346860.00|
            | 0.00,-10.00, 6392220.00|
            | 0.00, 0.00, 1.00|
        height: 22547
        width: 21710
        blockxsize: 256
        blockysize: 256
        bounds: (346860.0, 6166750.0, 563960.0, 6392220.0)

And the Datasets look like:

    rioxarray.RasterDataset
    Dimensions: y[latitude (m)]: 10, x[latitude (m)]: 10, z[time]: 2
    Data variables:
        blue	y[latitude (m)]: 10, x[latitude (m)]: 10, z[time]: 2
        green	y[latitude (m)]: 10, x[latitude (m)]: 10, z[time]: 2
    Profile:
        count: 2
        crs: 32722
        dtype: float64
        nodata: nan
        transform:
            | 3.00, 0.00, 466266.00|
            | 0.00,-3.00, 8084700.00|
            | 0.00, 0.00, 1.00|
        height: 10
        width: 10
        blockxsize: 10
        blockysize: 10
        bounds: (466266.0, 8084670.0, 466296.0, 8084700.0)