Bw-timex

* Added optional `starting_datetime` argument to `TimexLCA.build_timeline` explicitly. Before, it was buried in *args, which were passed to the underlying graph traversal (https://github.com/brightway-lca/bw_timex/pull/93)
* Allow multiple calls of `build_timeline` using the same `TimexLCA` object, e.g., using different `starting_datetime` (https://github.com/brightway-lca/bw_timex/pull/94)
* Fixed unintuitive rounding down of timestamps in dynamic characterization. 2024-12-31 would have been rounded to 2024, whereas 2025 makes more sense here. Now we round to the nearest year (https://github.com/brightway-lca/bw_timex/commit/21fa55bbcafee196447840c6518b5fee49fb6660)

* Added labels and units to the y-axis in `TimexLCA.plot_dynamic_characterized_inventory()`
* Fixed functions for creating labelled matrix representations

* Added utility function [`utils.add_temporal_distribution_to_exchange()`](https://github.com/brightway-lca/bw_timex/blob/a85349bdc43d98be559a7ce17d0b686098decec6/bw_timex/utils.py#L341) for easier temporalization of existing models
* Added more clarifying docstrings, created a "Getting Started" section in the docs as well as a [`getting_started.ipynb`](https://github.com/brightway-lca/bw_timex/blob/main/notebooks/getting_started.ipynb). Also overhauled existing example notebooks.
* Changed naming of the different score attributes to be more clear and [turned them into a property:](https://github.com/brightway-lca/bw_timex/blob/a85349bdc43d98be559a7ce17d0b686098decec6/bw_timex/timex_lca.py#L437)
* `TimexLCA.base_score` := `TimexLCA.static_lca.score` (no time-explicit information)
* `TimexLCA.static_score` := `TimexLCA.lca.score` (time-explicit LCI w/ static characterization)
* `TimexLCA.dynamic_score` := `TimexLCA.characterized_inventory["amount"].sum()` (time-explicit LCI w/ dynamic characterization, summed overall score)
* Fixed amounts for negative production amounts (https://github.com/brightway-lca/bw_timex/pull/83)

* Allow absolute temporal distributions (https://github.com/brightway-lca/bw_timex/pull/81)

* Moved dynamic characterization functionality completely to [dynamic_characterization](https://github.com/brightway-lca/dynamic_characterization). In the course of this, it was dynamic characterization was updated and is much faster now. See also https://github.com/brightway-lca/dynamic_characterization/pull/3

* Fixed some dependencies