test: add tests for text annotations

examples/gfl-local.html

tests/cypress/e2e/annotation.cy.js

tests/cypress/e2e/app.cy.js

tests/cypress/e2e/bookmark.cy.js

tests/cypress/e2e/config.cy.js

tests/cypress/e2e/content.cy.js

tests/cypress/e2e/header.cy.js

tests/cypress/support/globals.js

...AbtXV_Nr_39/GStA_I_HA_Rep76_Ve_Sekt1_AbtXV_Nr_39_007r.jpg

...AbtXV_Nr_39/GStA_I_HA_Rep76_Ve_Sekt1_AbtXV_Nr_39_007v.jpg

tests/mocks/gfl/build/support.e6949ffc.css

...3_l/Z_1819-06-03_l_page1/latest/annotationCollection.json

...9-06-03_l/Z_1819-06-03_l_page1/latest/annotationPage.json

...tapi/Z_1819-06-03_l/Z_1819-06-03_l_page1/latest/item.json

...3_l/Z_1819-06-03_l_page2/latest/annotationCollection.json

...9-06-03_l/Z_1819-06-03_l_page2/latest/annotationPage.json

...tapi/Z_1819-06-03_l/Z_1819-06-03_l_page2/latest/item.json

tests/mocks/gfl/textapi/Z_1819-06-03_l/manifest.json

...ocks/gfl/textapi/content/edited/Z_1819-06-03_l_page1.html

...ocks/gfl/textapi/content/edited/Z_1819-06-03_l_page2.html