Minimize certain dependencies that bloat the bundle size

[nichtich]

As discussed in #315 the size of Cocoda JavaScript can be reduced by only using the parts we need (see this). This step may also help to also reduce and customize boostrap CSS in a another step (see theming).

[stefandesu]

I adjusted the title of the issue to encompass other dependencies as well. The following dependencies are our biggest "offenders" in terms of bundle size:

• bootstrap-vue (should be removed if possible)
• lodash (should be removed or reduced to as few methods as possible)
• Vue.js (I guess it could be improved with Migrate to Vue.js 3 #583, but not sure how much difference it will make)
• FontAwesome icons (we could use unplugin-icons instead, like we did in coli-ana)

I have already (in 65b88c6) updated our own dependencies, cocoda-sdk and gbv-login-client, so that dependencies are not duplicated. This was an issue due to different dependency versions (e.g. axios in cocoda-sdk) and suboptimal build system (gbv-login-client; fixed by switching to ES modules and using the same build script as in cocoda-sdk).