Test suite sections support

[kuredoro]

It is common on the Olympiads to have several test case sections that test different constraints.

But how should we incorporate this into scold? Augment inputs.txt? Or have several inputs.txt for several sections?

Then how should the progress bar look like?

// Section 1
  Section 1 |**********     ||| 78/100

// Section 2
  Section 2 ||*****          || 7/15

// Section 3
  Section 3 |||********       | 45/50

idea 2

// Section 1
  Testing  [=========>     ] <<

// Section 2
  Testing O [====>          ] <

// Section 3
  Testing OF [=======>       ] 

// Section 4
  Testing OFO

idea 3

// Section 1
  Section 1  [=========>     ] 78/100
  Suite      [               ] 0/3


// Section 2
  Section 2  [====>          ] 7/15
  Suite      [======>        ] 1/3


// Section 3
  Section 3  [============>  ] 45/50
  Suite      [===============] 2/3