[CT-845] Rename try_* -> strict_*

[jtcohen6]

Follow-up to #5107, #5167

Let's rename:

• try_set → set_strict
• try_zip → zip_strict

Big idea is that strict_ methods:

• should raise a standard exception if the value cannot be converted to a set / yaml / json, zipped, etc
• should not not allow for a default value to gracefully (silently) fail over to

Timeline:

• Immediate (before Tuesday): Rename these for the second RC of v1.2.0
• Medium-term: Add fromjson_strict, tojson_strict, fromyaml_strict, toyaml_strict following the same pattern

[jtcohen6]

(I'm actually in the habit of typing → now)