[Feature] Add support to use any sql database as the metadata storage for embedchain apps

[deshraj]

Description

Changes:

• Use sqlalchemy instead of sqlite3 to support multiple databases so that Embedchain can be used easily in production setting
• Refactor code
• Remove stale code

Some more work to be done related to this PR. Will update the docs in the follow up PR.

Type of change

• New feature (non-breaking change which adds functionality)
• Refactor (does not change functionality, e.g. code style improvements, linting)

How Has This Been Tested?

• Unit Test

[codecov]

Codecov Report

Attention: 51 lines in your changes are missing coverage. Please review.

Comparison is base (6c12bc9) 56.58% compared to head (865f77e) 56.78%.

Files	Patch %	Lines
embedchain/core/db/database.py	71.69%	15 Missing ⚠️
embedchain/app.py	27.27%	8 Missing ⚠️
embedchain/embedchain.py	50.00%	7 Missing ⚠️
embedchain/memory/base.py	75.86%	7 Missing ⚠️
...versions/40a327b3debd_create_initial_migrations.py	69.56%	7 Missing ⚠️
embedchain/migrations/env.py	79.16%	5 Missing ⚠️
embedchain/client.py	83.33%	1 Missing ⚠️
embedchain/store/assistants.py	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1273      +/-   ##
==========================================
+ Coverage   56.58%   56.78%   +0.19%     
==========================================
  Files         146      150       +4     
  Lines        5954     6067     +113     
==========================================
+ Hits         3369     3445      +76     
- Misses       2585     2622      +37     

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[karlismea]

Getting an exception when starting my bot:
` File "/mnt/c/Users/karlis/Documents/chatApp/.venv/lib/python3.10/site-packages/embedchain/migrations/versions/40a327b3debd_create_initial_migrations.py", line 23, in upgrade
op.create_table(
File "", line 8, in create_table
File "", line 3, in create_table
File "/mnt/c/Users/karlis/Documents/chatApp/.venv/lib/python3.10/site-packages/alembic/operations/ops.py", line 1311, in create_table
return operations.invoke(op)
File "/mnt/c/Users/karlis/Documents/chatApp/.venv/lib/python3.10/site-packages/alembic/operations/base.py", line 445, in invoke
return fn(self, operation)
File "/mnt/c/Users/karlis/Documents/chatApp/.venv/lib/python3.10/site-packages/alembic/operations/toimpl.py", line 131, in create_table
operations.impl.create_table(table)
File "/mnt/c/Users/karlis/Documents/chatApp/.venv/lib/python3.10/site-packages/alembic/ddl/impl.py", line 366, in create_table
self._exec(schema.CreateTable(table))
File "/mnt/c/Users/karlis/Documents/chatApp/.venv/lib/python3.10/site-packages/alembic/ddl/impl.py", line 207, in _exec
return conn.execute(construct, multiparams)
File "/mnt/c/Users/karlis/Documents/chatApp/.venv/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 1408, in execute
return meth(
File "/mnt/c/Users/karlis/Documents/chatApp/.venv/lib/python3.10/site-packages/sqlalchemy/sql/ddl.py", line 180, in _execute_on_connection
return connection._execute_ddl(
File "/mnt/c/Users/karlis/Documents/chatApp/.venv/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 1519, in _execute_ddl
ret = self._execute_context(
File "/mnt/c/Users/karlis/Documents/chatApp/.venv/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 1839, in _execute_context
return self._exec_single_context(
File "/mnt/c/Users/karlis/Documents/chatApp/.venv/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 1979, in _exec_single_context
self._handle_dbapi_exception(
File "/mnt/c/Users/karlis/Documents/chatApp/.venv/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 2335, in _handle_dbapi_exception
raise sqlalchemy_exception.with_traceback(exc_info[2]) from e
File "/mnt/c/Users/karlis/Documents/chatApp/.venv/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 1960, in _exec_single_context
self.dialect.do_execute(
File "/mnt/c/Users/karlis/Documents/chatApp/.venv/lib/python3.10/site-packages/sqlalchemy/engine/default.py", line 924, in do_execute
cursor.execute(statement, parameters)
sqlalchemy.exc.OperationalError: (sqlite3.OperationalError) table ec_chat_history already exists
[SQL:
CREATE TABLE ec_chat_history (
app_id VARCHAR NOT NULL,
id VARCHAR NOT NULL,
session_id VARCHAR NOT NULL,
question TEXT,
answer TEXT,
metadata TEXT,
created_at TIMESTAMP,
PRIMARY KEY (app_id, id, session_id)
)

]`

[catmeme]

Same, this release caused a regression.