feat: add BSE module

[Fisherd99]

1. feat: add BSE module. Relevant tutorial will update in https://fisherd99.github.io/abacus-librpa-bse-tutorial.html.
   ATTENTION: BSE module depends on LibRI#11 Implement CVC algorithm and enhance LR class abacusmodeling/LibRI#11
2. feat: add ExcitonPlotter class.
3. add input parameter rpa_outdir and rpa_out_vel for Output files are not in the correct directories #7661

Reminder

• I have read AGENTS.md and docs/developers_guide/agent_governance.md.
• I have linked an issue or explained why this PR does not need one.
• I have added adequate unit tests and/or case tests, or explained why not.
  Not yet. The BSE module depends on LibRPA output files for reading. I don't know whether we can upload these files.
• I have listed the exact verification commands run and their results.
• I have described user-visible behavior changes, including INPUT parameter changes.
• I have explained core-module impact for ESolver, HSolver, ElecState, Hamilt, Operator, Psi, or other source/ changes.
• I have requested any needed governance exception below.

Linked Issue

Fix #7661

Unit Tests and/or Case Tests for my changes

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What's changed?

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Governance Notes

• INPUT/docs changes:
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[mohanchen]

please put any 'esolver' into source_esolver

[Fisherd99]

The ESolver_BSE class is a derived class of ESolverLR. Shall I move both of them?

[mohanchen]

That would be better, you could discuss this with @maki49

[Growl1234]

Just a note: the current code is not well encapsulated:

1. Generic LCAO builds now pull in BSE and ELPA dependencies unconditionally, which also causes the current CI failure.
2. ELPA-related macro handling, such as HAVE_SKEWSYMMETRIC, should not leak through BSE headers.