Add Koopa, SCINet, RevIN, MICN and TiDE, and update the docs

[WenjieDu]

What does this PR do?

1. fixing Add Koopa #377;
2. fixing Add SCINet #405;
3. fixing Add RevIN #404;
4. fixing Add MICN #395;
5. fixing Add TiDE #393;
6. fixing Positional encoding not applied in v0.5 imputation Nonstationary-Transformer and Pyraformer #411;
7. updating the docs and references;

Before submitting

• This PR is made to fix a typo or improve the docs (you can dismiss the other checks if this is the case).
• Was this discussed/approved via a GitHub issue? Please add a link to it if that's the case.
• I have commented my code, particularly in hard-to-understand areas.
• I have written necessary tests and already run them locally.

[coveralls]

Pull Request Test Coverage Report for Build 9064214275

Details

• 1103 of 1181 (93.4%) changed or added relevant lines in 37 files are covered.
• 5 unchanged lines in 2 files lost coverage.
• Overall coverage increased (+1.1%) to 83.606%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
pypots/nn/modules/koopa/backbone.py	38	39	97.44%
pypots/imputation/micn/core.py	33	35	94.29%
pypots/imputation/koopa/model.py	71	74	95.95%
pypots/imputation/micn/model.py	67	70	95.71%
pypots/imputation/revinscinet/model.py	70	73	95.89%
pypots/imputation/scinet/model.py	70	73	95.89%
pypots/imputation/tide/model.py	67	70	95.71%
pypots/nn/modules/revin/layers.py	41	46	89.13%
pypots/nn/modules/scinet/layers.py	98	107	91.59%
pypots/nn/modules/scinet/backbone.py	93	107	86.92%

Files with Coverage Reduction	New Missed Lines	%
pypots/nn/modules/etsformer/layers.py	2	96.6%
pypots/nn/modules/timesnet/layers.py	3	95.45%

Totals
Change from base Build 8998539337:	1.1%
Covered Lines:	9292
Relevant Lines:	11114

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💛 - Coveralls