feat: search iterations by cadence title instead of cadence ID

A few gitlab issues have triggered this MR:

• Cadence ID wasn't working as a filter (you can view iterations from other candences IDs in the UI so I suspect the ID is borked). So the CLI now uses cadence title to search for iterations and this is clearer from a CLI perspective
• Digital admissions has moved it's iteration cadence up a group into devops... however the gitlab API search is still acting as though this cadence is in a child group of devops... So include_descendants has been set to true, otherwise no DA iterations are found.

@bs461 I retested this for DA and spotted an issue. Example DA command and output:

GITLAB_TOKEN=<token-with-api-read> poetry run ucam-gitlab-stats --print-iterations --week-count=26 'Digital Admissions Sprints'

iteration start_date:2024-04-25  due_date:2024-05-08 id:369
estimate days: 0.0 weight: 68 ticket count 12

iteration start_date:2024-05-09  due_date:2024-05-22 id:378
estimate days: 0.0 weight: 8 ticket count 4

iteration start_date:2024-05-23  due_date:2024-06-05 id:387
estimate days: 0.0 weight: 0 ticket count 2

iteration start_date:2024-06-06  due_date:2024-06-19 id:396
estimate days: 0.0 weight: 3 ticket count 3

çiteration start_date:2024-06-20  due_date:2024-07-03 id:405
estimate days: 0.0 weight: 16 ticket count 8

iteration start_date:2024-07-04  due_date:2024-07-17 id:414
estimate days: 3.0 weight: 198 ticket count 49

çççiteration start_date:2024-07-18  due_date:2024-07-31 id:429
estimate days: 0.0 weight: 16 ticket count 28

iteration start_date:2024-08-01  due_date:2024-08-14 id:451
estimate days: 0.125 weight: 13 ticket count 10

iteration start_date:2024-08-15  due_date:2024-08-28 id:466
estimate days: 0.0 weight: 193 ticket count 57

iteration start_date:2024-08-29  due_date:2024-09-11 id:536
estimate days: 0.0 weight: 64 ticket count 38

iteration start_date:2024-09-12  due_date:2024-09-25 id:537
estimate days: 0.0 weight: 29 ticket count 13

iteration start_date:2024-09-26  due_date:2024-10-09 id:538
estimate days: 0.0 weight: 22 ticket count 12

iteration start_date:2024-10-10  due_date:2024-10-23 id:539
estimate days: 0.0 weight: 40 ticket count 22

Mean iteration capacity last 26 weeks: 51.53846153846154