feat(pie): two new alignTo layouts

[Ovilia]

feat(pie): support align to edge and labelLine mode #11381

Before:

After (two new layouts proposed):

API changes

The following are new options in this PR:

label: {
    alignTo: 'none', // 'none', 'labelLine', 'edge'. Works only when position is 'outer'. 'none' is for the previous design.

    // Closest distance between label and chart edge.
    // Works only position is 'outer' and alignTo is 'labelLine' or 'edge'.
    margin: '25%',

    // Works only position is 'outer' and alignTo is not 'edge'.
    bleedMargin: 10

    // Distance between text and labelLine. Previously, it's hard-coded as 3 in `labelLaout.js`.
    distanceToLabelLine: 5
}

For labelLine and edge, labelLine.length2 is used as the minimum length2.

Result and test

test/pie-alignTo.html provides test cases with different length2 and margin.

Limitations and todo

• We should consider more options for the label design like Label enhancement on pie. #11381.

[pissang]

bleedingMargin should be bleedMargin?