Add Volume charactristic calculator

[ChainsManipulator]

Add calculator function for volume characteristic for given intervals array using formula:
$$V=\displaystyle \prod_{j=1}^{m} \prod_{i=1}^{n_j} \Delta_{ij}$$
Where $\Delta_{ij}$ is an interval.

Examples

X = [2, 4, 2, 2, 4]
x_intervals = intervals(X, 'Start', 'Normal')
result = volume(x_intervals)
print(result)
> 12

X = ['B','B','A','A','C','B','A','C','C','B']
x_intervals = intervals(X, 'Start', 'Lossy')
result = volume(x_intervals)
print(result)
> 144

X = ['B','B','A','A','C','B','A','C','C','B']
x_intervals = intervals(X, 'Start', 'Normal')
result = volume(x_intervals)
print(result)
> 2160

X = ['B','B','A','A','C','B','A','C','C','B']
x_intervals = intervals(X, 'End', 'Normal')
result = volume(x_intervals)
print(result)
> 1152

X = ['B','B','A','A','C','B','A','C','C','B']
x_intervals = intervals(X, 'End', 'Redundant')
result = volume(x_intervals)
print(result)
> 17280

X = ['B','B','A','A','C','B','A','C','C','B']
x_intervals = intervals(X, 'End', 'Cycle')
result = volume(x_intervals)
print(result)
> 5184

---

X = ['C','C','A','C','G','C','T','T','A','C']
x_intervals = intervals(X, 'Start', 'Lossy')
result = volume(x_intervals)
print(result)
> 96

X = ['C','C','A','C','G','C','T','T','A','C']
x_intervals = intervals(X, 'Start', 'Normal')
result = volume(x_intervals)
print(result)
> 10080

X = ['C','C','A','C','G','C','T','T','A','C']
x_intervals = intervals(X, 'End', 'Normal')
result = volume(x_intervals)
print(result)
> 3456

X = ['C','C','A','C','G','C','T','T','A','C']
x_intervals = intervals(X, 'End', 'Redundant')
result = volume(x_intervals)
print(result)
> 362880

X = ['C','C','A','C','G','C','T','T','A','C']
x_intervals = intervals(X, 'End', 'Cycle')
result = volume(x_intervals)
print(result)
> 34560

---

X = ['C','C','C','C'] 
x_intervals = intervals(X, 'Start', 'Lossy')
result = volume(x_intervals)
print(result)
> 1

X =['C','C','C','C']  
x_intervals = intervals(X, 'Start', 'Normal')
result = volume(x_intervals)
print(result)
> 1

X = ['C','C','C','C'] 
x_intervals = intervals(X, 'End', 'Normal')
result = volume(x_intervals)
print(result)
> 1

X = ['C','C','C','C'] 
x_intervals = intervals(X, 'End', 'Redundant')
result = volume(x_intervals)
print(result)
> 1

X = ['C','C','C','C'] 
x_intervals = intervals(X, 'End', 'Cycle')
result = volume(x_intervals)
print(result)
> 1

No intervals

X = ['C','G'] 
x_intervals = intervals(X, 'End', 'Lossy')
result = volume(x_intervals)
print(result)
> 1

X = ['A','C','G','T'] 
x_intervals = intervals(X, 'End', 'Lossy')
result = volume(x_intervals)
print(result)
> 1

X = [2, 1] 
x_intervals = intervals(X, 'End', 'Lossy')
result = volume(x_intervals)
print(result)
> 1