Added cross product operation for vectors

[jesusbonilla]

• Implemented the cross product for R2 and R3 VectorValue gridap types
• Added tests to assess its implementation

[codecov-commenter]

Codecov Report

Merging #280 into master will decrease coverage by 0.00%.
The diff coverage is 66.66%.

@@            Coverage Diff             @@
##           master     #280      +/-   ##
==========================================
- Coverage   88.27%   88.26%   -0.01%     
==========================================
  Files         153      153              
  Lines        9960     9963       +3     
==========================================
+ Hits         8792     8794       +2     
- Misses       1168     1169       +1     

Impacted Files	Coverage Δ
src/TensorValues/Operations.jl	86.28% <66.66%> (-0.35%)	⬇️

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