Increase Project and Group test data

Per analysis in https://gitlab.com/gitlab-org/quality/performance/-/issues/475#note_738499727 that used data from self-managed customers, we increase GPT horizontal data from 250 groups with 10 projects each to 1000 groups with 10 projects each to adjust our test data with real data that customers have.

Additionally switches to use progress bar for horizontal data as previous format with new data size is too verbose. Example output:

GPT Data Generator v1.0.23 - opinionated test data for the GitLab Performance Tool
Checking that GitLab environment 'http://localhost' is available, supported and that provided Access Token works...
Environment and Access Token check complete - URL: http://localhost, Version: 14.6.0 3bc07a0be9c
Creating group gpt_2_new
Creating group gpt_2_new/many_groups_and_projects
Creating 50 groups with name prefix 'gpt-subgroup-' under parent group 'gpt_2_new/many_groups_and_projects'
Generating groups: 50 from 50 |=======================================================================================================>| Time: 00:00:04 Time: 00:00:04

Checking for existing projects under groups: 50 from 50 |=============================================================================>| Time: 00:00:01 Time: 00:00:01

Creating 10 projects each under 50 subgroups with name prefix 'gpt-project-'
Generating projects: 500 from 500 |===================================================================================================>| Time: 00:01:16 Time: 00:01:16

<-> Horizontal data: successfully generated after 1 minute 23 seconds!
█ GPT data generation finished after 1 minute 23 seconds.

• Create follow up for 1k results and to ensure that data clean up works and larger horizontal data is deleted correctly - #493

Closes #475