feat: insert utility

[andrewwood2]

Close #93

This is a tested and working solution, however, I think before merging it would be good to discuss:

1. if this is something that should be part of this package as it's fairly trivial for a user to create the same solution locally if they need it
2. are there edge cases that need to be covered (so far I've just thought about happy path)

[simoneb]

@Eomm please chime in

[Eomm]

if this is something that should be part of this package

I was thinking the same, but I must say that the SQL module requires some "automation" to let users migrate from an ORM to pure SQL (what I'm doing actually).
For this reason, I opened the issue to bridge this gap.

Talking off-topic, in my reasoning, the final goal would be to have utilities to build the SQL object to simplify:

• insert
• update
• dynamic select condition (the filter must be added if a condition is met)

For sure we must keep these utilities as plain as possible to avoid becoming an ORM 😆

As a final thought, maybe these utilities could become:

• an isolated file that need to be required (eg: const SQLBuilder = require('@nearform/sql/builder')
• or a list of examples/ in the documentation

In both cases, I think we are helping the developer.

are there edge cases that need to be covered

I think that if these uses cases show up as issues, they can be covered. For sure we need to define a reasonable set of "it just works" thinks.

[andrewwood2]

As discussed with @simoneb, moving the function to an example in the readme so that users can implement locally if desired.