add support of bulk operations for ORM in ORACLE and SQLite backends

[vyskubov]

Hello everyone,

I am excited to submit this pull request, which (re)introduces support for bulk operations in the SOCI library's ORM (Object-Relational Mapping) functionality. This work is based on the initial groundwork laid by @abc100m, and I have built upon their contributions to enhance the capabilities of the library.

I would appreciate it if the community could review and provide feedback on the changes. Your insights and suggestions are valuable in ensuring the quality and effectiveness of this new feature.

Thank you for your attention and consideration. I look forward to collaborating with you all to further enhance the SOCI library.

Best regards, Aleksey

[vyskubov]

Thanks for reviewing!

1. I have reverted all the whitespace-only changes. I apologize for mistakenly committing them. Regarding the replacement of at(pos) with [pos], these changes were already present in the original PR, so I simply included them as-is. However, I have now reverted these changes for the time being. It's worth mentioning that the usage of at(pos) and [pos] in this file is inconsistent, which could be addressed in a separate PR.
2. and 3. I will address these points later.

Thank you again.

[vadz]

1. I have reverted all the whitespace-only changes.

Thanks!

Regarding the replacement of at(pos) with [pos], these changes were already present in the original PR, so I simply included them as-is.

Sorry for not realizing this.

However, I have now reverted these changes for the time being. It's worth mentioning that the usage of at(pos) and [pos] in this file is inconsistent, which could be addressed in a separate PR.

I agree that inconsistencies should be fixed but it's definitely better to do them in a separate PR. Thanks for fixing this up too!

[asmwarrior]

What is the status of this PR, I think the bulk adding is a very important feature for soci.

I have a similar discussion issue discussion here: ORM: What is the correct way to bulk add a lot of rows? · Issue #1066 · SOCI/soci, in the issue, I have to use a for loop to add many rows, but I do need a simple way to do that.

Thanks.

[vyskubov]

I apologize for for temporarily abandoning this PR. I would like to complete the work on it; however, I currently have more urgent tasks to attend to.

Furthermore, I do not have a readily available development environment on Windows and FreeBSD. Any assistance would be greatly appreciated.

Thank you.