Add ocean alklinity enhancement

[katarkow]

Purpose of this PR

1. Add ocean alkalinity enhancement (OAE) to the CDR module. The option is off by default and can be added to the CDR portfolio via switch cm_33OAE.
2. Since OAE is quite cheap, switching it on without limits might lead to infeasibilities, especially in end-of-century scenarios. There are no direct limitations, so I added it to quantity targets @Renato-Rodrigues such that esp Leon can limit global deployment.
3. Together with remind2#629, this PR fixes the summation errors I introduced when separating atmospheric emissions from DAC and captured emissions from burning gas for DAC. @fschreyer
4. Introduces capture rate of 90% for gas used for CDR which was missing so far. @strefler

Type of change

• New feature
• This change requires a documentation update

Checklist:

• My code follows the coding etiquette
• I performed a self-review of my own code
• I explained my changes within the PR, particularly in hard-to-understand areas
• I checked that the in-code documentation is up-to-date
• I adjusted the reporting in remind2 where it was needed ( remind2#629)
• All automated model tests pass (FAIL 0 in the output of make test)
• The changelog CHANGELOG.md has been updated correctly

• Test runs are here:
  SSP2-NPi: /p/tmp/katarkow/remind/OAE_6c9a0dd/output/SSP2-NPi_2024-08-01_18.51.03
  default SSP2-PkBudg650: /p/tmp/katarkow/remind/OAE_6c9a0dd/output/SSP2-PkBudg650_2024-08-01_20.28.50
  SSP2-PkBudg650 with OAE: /p/tmp/katarkow/remind/OAE_6c9a0dd/output/SSP2-PkBudg650_2024-08-01_20.28.50
• Comparison of results (what changes by this PR?): /p/tmp/katarkow/remind/OAE_6c9a0dd/output/cs2_output/AMT_Pk650-Pk650-OAE_Pk650.pdf (The latest AMT from 18.07.24 18:16 does not include the transport sector changes merged by Johanna the same day at 20:59, so I'm not sure how helpful the comparison)