[Linalg] Add basic linalg ops
This CL adds linalg.dot, linalg.matvec and linalg.matmul ops with the proper roundtripping test. These are the first LinalgOp that operate on views and that will lower to library calls.
Linalg ops exhibit some common properties and behavior that are modeled with Traits.
A LinalgOp is defined as a generic Op that operates on input and output views (passed as operands) and has the following properties:
1. a number of input and outputs captured by the `NInputsAndOutputs` trait.
2. a list of ranks for each operand captured by the `ViewRanks` trait.
3. a set of parallel, reduction and windowing loops captured by `NLoopTypes` trait.
These represent are a first set of generic properties that will enable the definition of generic linear algebra operations and the properties necessary for upcoming transformations.
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PiperOrigin-RevId:
244912754