[CT-2266] [Feature] Make MAXIMUM_SEED_SIZE configurable

[acurtis-evi]

Is this your first time submitting a feature request?

• I have read the expectations for open source contributors
• I have searched the existing issues, and I could not find an existing issue for this feature
• I am requesting a straightforward extension of existing dbt functionality, rather than a Big Idea better suited to a discussion

Describe the feature

There is a need to allow the 1MB seed limit to be relaxed

Slack thread for context
https://getdbt.slack.com/archives/C50NEBJGG/p1677856760823939

Describe alternatives you've considered

No response

Who will this benefit?

No response

Are you interested in contributing this feature?

No response

Anything else?

No response

[dbeatty10]

Thanks for opening this issue and the associated PR @acurtis-evi !

Related to #6875

Current behavior

From the caveats to state comparison for seeds:

dbt stores a file hash of seed files that are <1 MB in size. If the contents of these seeds is modified, the seed will be included in state:modified.

Proposed behavior

Lightly edited from here:

• add a DBT_MAXIMUM_SEED_SIZE env variable (expressed in MiB)
• default to 1
• setting DBT_MAXIMUM_SEED_SIZE to 0 would remove the limit entirely
  • i.e., if the derived constant MAXIMUM_SEED_SIZE is 0, then there is no limit to the seed size

Functional approval

@jtcohen6 indicated the following in the discussion in Slack:

Ok! I'm not strictly opposed to either/both of:

• making this limit configurable (you accept slowness as trade-off)
• updating the logic to better handle larger files — if one of you would be interested in contributing that (not something we'd be prioritizing soon ourselves)

[noppaz]

This aims to be solved in #7125.
There is a documentation update issue for it here dbt-labs/docs.getdbt.com#2958