samconfig.toml support

related: #1437

> parse SAM toml configs and use that for `Deploy lambda` command?

## Problem

- customers cannot use samconfig.toml
- Toolkit sam run/debug launch configs do not have well-specified rules for precedence when `sam.buildArguments` is given.
- E.g. the code path is remapping too many things for `sam.buildArguments` to be reliable for anything path-related (such as `--cache`)

## Proposal

- Remove/deprecate launch config options that are redundant/overlap with `sam.buildArguments` and `sam.localArguments`
- Toolkit would need to auto-update/migrate existing launch configs.
- `aws` field? #2380
- Move to samconfig.toml as the primary source of truth?
- If we move to `samconfig.toml` then we should looks towards supporting a schema. A major benefit of the launch config is auto-complete and documentation built-in.

The issue does not name files or tests. Start by tracing the Deploy lambda command and the handling of sam.buildArguments and sam.localArguments, then map how launch-config precedence and migration currently work. Done would require an agreed scope for samconfig.toml parsing, precedence, launch-config migration, and schema support.

Written by the indexing model from the issue text.