[Enhancement] Add a properties to configure max-archive-size option

Hi.
We have some big database to backup and we got some issue with ephemeral storage usage.
We was able to manage the useg setting max-archive-size, but to do so we have tu use the additionalCommandArgs property.

to polish the yaml would be great to have a property in [DataBackupConfiguration](https://github.com/cloudnative-pg/barman-cloud/blob/v0.4.0/pkg/api/config.go#L274) [¶](https://pkg.go.dev/github.com/cloudnative-pg/barman-cloud/pkg/api#DataBackupConfiguration) and some documentation line about Ephemeral storage consumption and parameters like "jobs".

从 pkg/api/config.go 中的 DataBackupConfiguration 开始，然后查看现有的关于 additionalCommandArgs、max-archive-size、临时存储消耗和 jobs 的文档。完成的标准是配置直接公开 max-archive-size，并记录相关的存储指导。

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