[SPARK-3975] Added support for BlockMatrix addition and multiplication

Support for multiplying and adding large distributed matrices!

Author: Burak Yavuz <brkyvz@gmail.com>
Author: Burak Yavuz <brkyvz@dn51t42l.sunet>
Author: Burak Yavuz <brkyvz@dn51t4rd.sunet>
Author: Burak Yavuz <brkyvz@dn0a221430.sunet>
Author: Burak Yavuz <brkyvz@dn0a22b17d.sunet>

Closes #4274 from brkyvz/SPARK-3975PR2 and squashes the following commits:

17abd59 [Burak Yavuz] added indices to error message
ac25783 [Burak Yavuz] merged masyer
b66fd8b [Burak Yavuz] merged masyer
e39baff [Burak Yavuz] addressed code review v1
2dba642 [Burak Yavuz] [SPARK-3975] Added support for BlockMatrix addition and multiplication
fb7624b [Burak Yavuz] merged master
98c58ea [Burak Yavuz] added tests
cdeb5df [Burak Yavuz] before adding tests
c9bf247 [Burak Yavuz] fixed merge conflicts
1cb0d06 [Burak Yavuz] [SPARK-3976] Added doc
f92a916 [Burak Yavuz] merge upstream
1a63b20 [Burak Yavuz] [SPARK-3974] Remove setPartition method. Isn't required
1e8bb2a [Burak Yavuz] [SPARK-3974] Change return type of cache and persist
e3d24c3 [Burak Yavuz] [SPARK-3976] Pulled upstream changes
fa3774f [Burak Yavuz] [SPARK-3976] updated matrix multiplication and addition implementation
239ab4b [Burak Yavuz] [SPARK-3974] Addressed @jkbradley's comments
add7b05 [Burak Yavuz] [SPARK-3976] Updated code according to upstream changes
e29acfd [Burak Yavuz] Merge branch 'master' of github.com:apache/spark into SPARK-3976
3127233 [Burak Yavuz] fixed merge conflicts with upstream
ba414d2 [Burak Yavuz] [SPARK-3974] fixed frobenius norm
ab6cde0 [Burak Yavuz] [SPARK-3974] Modifications cleaning code up, making size calculation more robust
9ae85aa [Burak Yavuz] [SPARK-3974] Made partitioner a variable inside BlockMatrix instead of a constructor variable
d033861 [Burak Yavuz] [SPARK-3974] Removed SubMatrixInfo and added constructor without partitioner
8e954ab [Burak Yavuz] save changes
bbeae8c [Burak Yavuz] merged master
987ea53 [Burak Yavuz] merged master
49b9586 [Burak Yavuz] [SPARK-3974] Updated testing utils from master
645afbe [Burak Yavuz] [SPARK-3974] Pull latest master
beb1edd [Burak Yavuz] merge conflicts fixed
f41d8db [Burak Yavuz] update tests
b05aabb [Burak Yavuz] [SPARK-3974] Updated tests to reflect changes
56b0546 [Burak Yavuz] updates from 3974 PR
b7b8a8f [Burak Yavuz] pull updates from master
b2dec63 [Burak Yavuz] Pull changes from 3974
19c17e8 [Burak Yavuz] [SPARK-3974] Changed blockIdRow and blockIdCol
5f062e6 [Burak Yavuz] updates with 3974
6729fbd [Burak Yavuz] Updated with respect to SPARK-3974 PR
589fbb6 [Burak Yavuz] [SPARK-3974] Code review feedback addressed
63a4858 [Burak Yavuz] added grid multiplication
aa8f086 [Burak Yavuz] [SPARK-3974] Additional comments added
7381b99 [Burak Yavuz] merge with PR1
f378e16 [Burak Yavuz] [SPARK-3974] Block Matrix Abstractions ready
b693209 [Burak Yavuz] Ready for Pull request