Extract package "@eventespresso/types"

[alexkuc]

~Wait for PR #1295 to be merged first!~

The scope of this PR:

• review types and refactor them where possible (easy cases)
• mark common data-related types as TODOs for next PR
• create package types as Level-0

[alexkuc]

As of commit b5bfaf8167cb0126a852dca4e3fe4cce87a70938, the following has passed locally:

• linter ✅
• build ✅
• unit tests ✅
• e2e tests ✅

[alexkuc]

As of commit 5a65841c3b50d673534035ee7aaa3f91e105064f, the following has passed locally:

• linter ✅
• build ✅
• unit tests ✅
• e2e tests ✅

[alexkuc]

Current base: 4cbe1fb5a81bbdacbd2e480cee118ae9c0e1234c

[alexkuc]

As of commit eccabb543582af8326c4aee0c6b488a4a6d79b79, the following has passed locally:

• linter ✅
• build ✅
• unit tests ✅
• e2e tests ✅

[alexkuc]

Gonna test latest commit just-in-case before merging

[alexkuc]

Running locally:

• rm -fr node_modules && yarn install ✅
• yarn lint ✅
• yarn build ✅
• yarn jest --maxWorkers=4 ✅
• yarn test (e2e repo) ✅

[alexkuc]

The latest local commit sha is e9c8b99