Refactor context management for program builders

[shumpohl]

This PR replaces PulseTemplate._create_program(**a_lot_of__kwargs) with PulseTemplate._build_program(program_builder).

It moves all the information about the current scope, transformations, channel and measurement mappings into the program builder.

• Add ProgramBuilder.build_context: BuildContext: A dataclass with mutable information like the current scope
• Add ProgramBuilder.build_settings: BuildSettings: A dataclass with constant information like which templates to translate into a single waveform
• Add Program.get_defined_channels.
• Add ProgramBuilder.override to modify the current built settings/context.
• Add ProgramBuilder.with_mappings for MappingPT
• Add ProgramBuilder.with_transformation for arithmetic and channel modification PTs
• Add ProgramBuilder.with_metadata for a semi standadized metadata passing. The only read metadata right now is the minimal sample rate.
• Remove ProgramBuilder.inner_scope because it is no longer required.

To reduce code duplication the PR contains the BaseProgramBuilder class which contains some default implementations for context management which are shared between the loop and linspace builder.

TODO:

• fix other tests
• motivate split between BuildSettings and BuildContext or merge them
• Transform the PR text into a newspiece

[github-actions]

Test Results

    6 files      6 suites   7m 3s ⏱️
1 234 tests 1 172 ✅  62 💤 0 ❌
7 404 runs  7 032 ✅ 372 💤 0 ❌

Results for commit 1c6516f.

♻️ This comment has been updated with latest results.

[shumpohl]

@Nomos11 triggered by properly implementing minimal sample rate