Check BCs for periodicity for periodic Tree & Structured meshes

[DanielDoehring]

Motivated by #752

This puts out warnings if a mesh with periodic boundaries is used, but still BCs are supplied. The converse case, where a non-periodic mesh and periodic BCs are paired returns an error, so no additional treatment is added here.

[github-actions[bot]]

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[codecov[bot]]

Codecov Report

Attention: Patch coverage is 96.15385% with 1 lines in your changes are missing coverage. Please review.

Project coverage is 96.30%. Comparing base (4bf61a0) to head (2b47577).

Files	Patch %	Lines
src/meshes/tree_mesh.jl	50.00%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #1860 +/- ## ========================================== - Coverage 96.30% 96.30% -0.00% ========================================== Files 438 438 Lines 35577 35603 +26 ========================================== + Hits 34259 34284 +25 - Misses 1318 1319 +1 ``` | [Flag](https://app.codecov.io/gh/trixi-framework/Trixi.jl/pull/1860/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=trixi-framework) | Coverage Δ | | |---|---|---| | [unittests](https://app.codecov.io/gh/trixi-framework/Trixi.jl/pull/1860/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=trixi-framework) | `96.30% <96.15%> (-<0.01%)` | :arrow_down: | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=trixi-framework#carryforward-flags-in-the-pull-request-comment) to find out more.

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