[Cashtab] Clean up mock files and standardize mock imports for component integration tests

Summary:
T3444

We are re-using many mocks and have some legacy mocks that are not used at all.

In cases where different components are using the same mock stored in different files, point to the same mock and delete the repeated mock. Delete unused mocks. Remove @generated from mocks files as, while some are copy-pasted from chronik output, in general they are not @generated and should be reviewed.

Test Plan: npm test

Reviewers: #bitcoin_abc, PiRK

Reviewed By: #bitcoin_abc, PiRK

Differential Revision: https://reviews.bitcoinabc.org/D15581