v1.0.0

This is the release of the version v1.0.0, which is the stable version of the project.

Release notes:

1. [Important] This is the first stable release of the project.
2. [Change] Merge Contract and Contracts into Contract, and Contract_ and Contracts_ ito Contract_.
3. [Change] Merge relabel and relabels into relabel, and relabel_ and relabels_ into relabel_.
4. [New] Add an optional argument min_blockdim to svd_truncate to define a minimum dimension for each block.
5. [New] Add Eig/Eigh functions for Block UniTensor.
6. [New] Add Lancos-like algoirthm, Lanczos_Exp, to approximate exponential operator acting on a state.
7. [Change] Migrate cuTENSOR APIs to the version 2.
8. [Change] reshape_ and permute_ to return the object itself instead of None.
9. [Change] Remove the magma dependency.
10. [Enhance] Optimize the contraction order finding algorithm.