Generate date time test data from CLDR sources

[echeran]

No description provided.

[sven-oly]

Will this be for data on and before ICU75?

[sffc]

Note: this issue is about reading the CLDR date time test data instead of generating the test data with Node.js. It can be done in parallel with efforts involving improvements to the CLDR test data.

[sven-oly]

PR #329 references this. However, the data generation needs to be examined because many test failures occur when comparing ICU4J/C/X output with the expected text.