refactor(l2): separated configs for prover_client and sequencer

[fborello-lambda]

Motivation

When running the prover_client as a standalone component the config.toml wasn't being parsed.
Ideally we should parse it before we run the prover_client.

Description

• The ConfigMode enum is proposed to parse the .toml for the Sequencer or the ProverClient
• The prover_client parses the prover_client_config.toml and creates a .env.prover file
• Created new envars to set the:
  • CONFIGS_PATH
  • SEQUENCER_CONFIG_FILE
  • PROVER_CLIENT_CONFIG_FILE
  • The references were updated in the Makefile

This change also enables us to change the SEQUENCER_CONFIG_FILE easily keeping it in the configs dir and switching the Makefile's variable. (Useful when testing locally and with a testnet).

Closes #2053

[github-actions]

Lines of code report

Total lines added: 361
Total lines removed: 37
Total lines changed: 398

Detailed view

+----------------------------------------------+-------+------+
| File                                         | Lines | Diff |
+----------------------------------------------+-------+------+
| ethrex/cmd/ethrex/initializers.rs            | 336   | +4   |
+----------------------------------------------+-------+------+
| ethrex/crates/l2/contracts/deployer.rs       | 761   | -9   |
+----------------------------------------------+-------+------+
| ethrex/crates/l2/errors.rs                   | 0     | -27  |
+----------------------------------------------+-------+------+
| ethrex/crates/l2/l2.rs                       | 4     | -1   |
+----------------------------------------------+-------+------+
| ethrex/crates/l2/prover/src/main.rs          | 30    | +8   |
+----------------------------------------------+-------+------+
| ethrex/crates/l2/utils/config/errors.rs      | 43    | +26  |
+----------------------------------------------+-------+------+
| ethrex/crates/l2/utils/config/mod.rs         | 109   | +32  |
+----------------------------------------------+-------+------+
| ethrex/crates/l2/utils/config/toml_parser.rs | 291   | +291 |
+----------------------------------------------+-------+------+