Merge pull request #17523 from prashanth018/mat_expo_1
Matrix exponentiation using Scaling and Squaring Algorithm.
[contributed by @prashanth018 and reviewed by Lydia and @npadmana]
'expm' method takes in an N*N array as an argument and returns an exponentiated
matrix of same dimension. Time Complexity of this approach is approximately O(15.n^3)
 Awad H. Al-Mohy and Nicholas J. Higham (2009)
"A New Scaling and Squaring Algorithm for the Matrix Exponential."
SIAM Journal on Matrix Analysis and Applications.
31 (3). pp. 970-989. ISSN 1095-7162
Passed a full paratest with futures and the built docs look good
Modified Files: A test/library/packages/LinearAlgebra/correctness/no-dependencies/testExpm.chpl