remove mention of building blocks and blocks from documentation

[odscjen]

closes #1347

Used primarily "objects" as per the section of the style guide that states

When describing JSON schema * “object”, not “block”

but did use "sub-schema" in a few instances.

There's 2 uses of "block" in the schema itself but they'll be covered by a PR for #850

[duncandewhurst]

I think the style guide needs updating to reflect the agreement in #1347, my understanding of which is that we should use 'sub-schema' when referring to the definitions in the schema and 'object' when referring to their representation in data. That aligns with the sentence that appears at the start of the sub-schema reference in OC4IDS, which explains the relationship between sub-schemas and objects.

Most of my suggested changes are based on that understanding, except where I've suggested replacing 'object' with 'array' in order to align with the types in the schema.

[jpmckinney]

There are two occurrences in documentType.csv (subContract, billOfQuantity) where we can just delete the last clause. If those aren't handled by other PRs or issues, let's fix them here.

Noting that use of "block" on two occasions in the Milestone sub-schema will be fixed by #850

[odscjen]

I've removed the final sentences from both of those codes in documentType as I don't they were being picked up anywhere else

[jpmckinney]

I started reviewing, but having now read more content using the different available terms, I think we should prefer "field", unless the word "object" or "array" is contributing to the understanding of the sentence. Can you review with that in mind?

We can update the handbook accordingly.

[odscjen]

added an issue to the handbook repo to update the style guide open-contracting/standard-development-handbook#285

[odscjen]

@jpmckinney are you ok with the suggestions in open-contracting/standard-development-handbook#285 (comment), if so I'll redo this PR with those all in mind