230 tutorial gcp opt (#253)

* Draft tutorial

* Created ttensor/reconstruct tutorial in master.

* Moved to proper location.

* Suppress output

* Formatting.

* Draft of GCP_OPT tutorial. Requires resolving issue #252.

* Potential fix for ValueError in optimizers.

* autoformat

* Removed from main until completed in branch 248-tutorial-partial-reconstruction-of-a-tucker-tensor.

* Restored from upstream main.

* Auto formatting.

* Commenting out cells that use matplotlib.

* Draft tutorial

* Moved to proper location.

* Suppress output

* Formatting.

* Draft of GCP_OPT tutorial. Requires resolving issue #252.

* Auto formatting.

* Commenting out cells that use matplotlib.

* Sptensor mask (#259)

* SPTENSOR: Fix Mask, using tt_ismember_rows incorrectly

* PYTTB_UTILS: Design away error:
* Make it more obvious member rows might not match

* LaTeX

* Decrease the number of maximum iterations for notebook examples to try and avoid time out issues.

* Closes #230

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Co-authored-by: Jeremy Myers <jermyer@sandia.gov>
Co-authored-by: Danny Dunlavy <dmdunla@sandia.gov>
Co-authored-by: Nick <24689722+ntjohnson1@users.noreply.github.com>