rtc: Add data model for "Cesiones Periodo" entries

[jtrh]

Add a data model for "Cesiones Periodo" entries.

This commit was taken from:

• https://github.com/fyntex/lib-cl-sii-api-python/commit/0bafb09711cfe1695e27f82eeeb8686b8f8626d3
• https://github.com/fyntex/lib-cl-sii-api-python/commit/d7dd76d713cd429ca1d3c8e08da5f7ede2c95649
• https://github.com/fyntex/lib-cl-sii-api-python/commit/60eda63de7d8fd54ddf681ad54709f3752bc8e7c

Additional changes:

• Rename files.
• Fix imports.
• Add and remove some empty lines.

Ref: https://github.com/fyntex/lib-cl-sii-api-python/issues/209.

[codecov-io]

Codecov Report

Merging #172 (694e260) into develop (a7a78e1) will decrease coverage by 1.37%.
The diff coverage is 55.04%.

@@             Coverage Diff             @@
##           develop     #172      +/-   ##
===========================================
- Coverage    78.14%   76.77%   -1.38%     
===========================================
  Files           26       27       +1     
  Lines         1725     1834     +109     
  Branches       279      308      +29     
===========================================
+ Hits          1348     1408      +60     
- Misses         256      282      +26     
- Partials       121      144      +23     

Impacted Files	Coverage Δ
cl_sii/rtc/data_models_cesiones_periodo.py	55.04% <55.04%> (ø)

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[glarrain]

@jtrh It would be nice to convert them to pydantic dataclasses and be able to remove most of the awful type checking code, don't you agree?

[jtrh]

It would be nice to convert them to pydantic dataclasses and be able to remove most of the awful type checking code, don't you agree?

@glarrain The AEC and generic Cesion data models are like that. After they're finished it'll be the turn of CesionesPeriodoEntry.