Add Amount and Source messages

[skearnes]

Related to #506

• Adds an Amount message to avoid duplicated oneof fields.
  • I chose to include volume_includes_solutes in the Amount message. This is similar to the other use cases for Amount where not all of the fields will be suitable (e.g. moles for CrudeComponent).
  • The field is named aliquot_amount in ReactionWorkup.
• Adds a Source message to wrap various vendor metadata.
  • This is a ride-along; let me know if you think we should drop it.

I'll update the tests once we're aligned on the proto changes.

[codecov[bot]]

Codecov Report

Merging #507 (6318bb2) into product-characterization (5ea1dd1) will decrease coverage by 0.75%. The diff coverage is 43.75%.

@@                     Coverage Diff                      @@
##           product-characterization     #507      +/-   ##
============================================================
- Coverage                     76.27%   75.51%   -0.76%     
============================================================
  Files                            24       24              
  Lines                          2154     2169      +15     
  Branches                        486      492       +6     
============================================================
- Hits                           1643     1638       -5     
- Misses                          360      380      +20     
  Partials                        151      151              

Impacted Files	Coverage Δ
ord_schema/validations.py	69.46% <16.66%> (-1.59%)	:arrow_down:
ord_schema/visualization/filters.py	53.17% <22.22%> (ø)
ord_schema/message_helpers.py	84.64% <70.58%> (+0.05%)	:arrow_up:
ord_schema/resolvers.py	74.71% <100.00%> (ø)
ord_schema/templating.py	94.82% <100.00%> (ø)
ord_schema/interface/ord_client.py	39.47% <0.00%> (-21.06%)	:arrow_down:

[skearnes]

PTAL